TW201320814A - Led lighting systems and methods for constant current control in various operation modes - Google Patents

Abstract

System and method for providing at least an output current to one or more light emitting diodes. The system includes a control component configured to receive at least a demagnetization signal, a sensed signal and a reference signal and to generate a control signal based on at least information associated with the demagnetization signal, the sensed signal and the reference signal, and a logic and driving component configured to receive at least the control signal and output a drive signal to a switch based on at least information associated with the control signal. The switch is connected to a first diode terminal of a diode and a first inductor terminal of an inductor. The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal.

Description

System and method for providing output current to a light emitting diode

The present invention relates to an integrated circuit. More specifically, the present invention provides a lighting system and method for constant current control in various modes of operation. Merely by way of example, the invention has been applied to one or more light emitting diodes. However, it will be appreciated that the invention has a broader range of applications.

In general, conventional lighting systems for light emitting diodes (LEDs) often use a floating buck converter. This type of LED lighting system is typically small in size and cost effective. Figure 1 is a simplified diagram showing a conventional LED lighting system with a buck converter. The illumination system 100 includes a pulse width modulation (PWM) controller 110, a power switch 120, a diode 130, an inductor 140, capacitors 150 and 152, and a sense resistor 160. Additionally, illumination system 100 receives an input voltage and provides a lamp current and a lamp voltage to one or more LEDs 190.

As shown in FIG. 1, power switch 120 includes terminals 122, 124, and 126. The PWM controller 110 outputs a drive signal 112 and receives a current sense signal 114. The drive signal 112 corresponds to a switching period (eg, T _s ). For example, the power switch 120 is a MOS transistor. In another example, power switch 120 is a bipolar transistor (eg, an NPN bipolar transistor). In yet another example, the power switch 120 is an insulated gate bipolar transistor (IGBT).

Increasing the constant current control technique has become very important so that a constant lamp current can be obtained in DCM mode, CCM mode, and critical conduction mode (CRM) and high power factor and precision control can be achieved.

The present invention relates to an integrated circuit. More specifically, the present invention provides illumination systems and methods for constant current control in various modes of operation. Merely by way of example, the invention has been applied to one or more light emitting diodes. However, it will be appreciated that the invention has a broader range of applications.

In accordance with another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a control component configured to receive at least a demagnetization signal, a sensing signal, and a reference signal, and based at least on demagnetization The signal, the sense signal, and the information associated with the reference signal generate a control signal; and a logic and drive component configured to receive at least the control signal and output a drive signal to the switch based on at least information associated with the control signal. The switch is connected to the first diode terminal of the diode and the first inductor terminal of the inductor. The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal. The second diode terminal and the second inductor terminal are configured to provide at least an output current to the one or more light emitting diodes. The control signal is configured to adjust the output current to a predetermined constant current magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes: receiving at least a demagnetization signal, a sensing signal, and a reference signal; processing and demagnetizing signals, sensing signals, and reference signals Associated information; and generating a control signal based at least on information associated with the demagnetization signal, the sensed signal, and the reference signal. Additionally, the method includes: receiving at least a control signal; processing information associated with the control signal; and outputting a drive signal to a switch coupled to the first diode terminal of the diode and the first inductor terminal of the inductor. The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal. The second diode terminal and the second inductor terminal are configured to provide at least an output current to the one or more light emitting diodes. Moreover, the method includes adjusting the output current to a predetermined size based at least on information associated with the control signal.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a first signal processing component configured to receive at least a sensing signal and generate a first signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the system includes: a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and generate a third signal; and a comparator configured to process The third signal and the information associated with the sensing signal and the comparison signal are generated based at least on information associated with the third signal and the sensing signal. Additionally, the system includes a signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for the demagnetization process. For each of the one or more switching cycles, the first signal represents a multiplication result of the first sum value of the on-time period and the demagnetization period and the second sum value of the first current magnitude and the second current magnitude, and the second The signal indicates the switching period multiplied by the predetermined current magnitude. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal represents the integrated cycle-by-cycle accumulated difference. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal Information associated with the second signal; and generating a third signal based on at least information associated with the first signal and the second signal. Moreover, the method includes: processing information associated with the third signal and the sensed signal; generating a comparison signal based on at least information associated with the third signal and the sensed signal; receiving at least the comparison signal; at least based on correlating with the comparison signal The information generates a modulated signal; receives the modulated signal; and outputs the drive signal based at least on information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-period and a demagnetization period. For each of the one or more switching cycles, the first signal represents a multiplication result of the first sum value of the on-time period and the demagnetization period and the second sum value of the first current magnitude and the second current magnitude, and the second The signal indicates the switching period multiplied by the predetermined current magnitude. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The processing for processing information associated with the first signal and the second signal includes integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal representing the integrated The difference is accumulated step by cycle. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a first signal processing component configured to receive at least a sensing signal and generate a first signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the system includes: a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and generate a third signal; and a comparator configured to process The third signal and the information associated with the sensing signal and the comparison signal are generated based at least on information associated with the third signal and the sensing signal. Additionally, the system includes a signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for the demagnetization process. For each cycle of one or more switching cycles, the first signal represents the sum of the first multiplication result and the second multiplication result, and the second signal represents the switching period multiplied by the predetermined current magnitude. The first multiplication result is equal to the sum of the first current magnitude and the second current magnitude multiplied by the on-time period. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The second multiplication result is equal to two times the demagnetization period and multiplied by the third current magnitude, and the third current magnitude represents the inductor current at the middle of the on period. The integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal represents the integrated cycle-by-cycle accumulated difference. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal Information associated with the second signal; and generating a third signal based on at least information associated with the first signal and the second signal. Moreover, the method includes: processing information associated with the third signal and the sensing signal; generating a comparison signal based on at least information associated with the third signal and the sensing signal; receiving at least the comparison signal; and based at least on the comparison signal The associated information produces a modulated signal. And, the method includes: receiving a modulated signal; and outputting the drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-period and a demagnetization period. For each cycle of one or more switching cycles, the first signal represents the sum of the first multiplication result and the second multiplication result, and the second signal represents the switching period multiplied by the predetermined current magnitude. The first multiplication result is equal to the sum of the first current magnitude and the second current magnitude multiplied by the on-time period. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The second multiplication result is equal to two times the demagnetization period and multiplied by the third current magnitude, and the third current magnitude represents the inductor current at the middle of the on period. The processing for processing information associated with the first signal and the second signal includes integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal representing the integrated The difference is accumulated step by cycle. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes: a first sample and hold and voltage to current conversion component configured to receive at least a sensed signal and generate a A current signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch. Additionally, the system includes: a second sample and hold and voltage to current conversion component configured to receive at least the sensed signal and generate a second current signal; and a signal amplification and voltage to current conversion component configured to receive at least the sensing The signal also produces a third current signal. Additionally, the system includes: a current signal generator configured to generate a fourth current signal; and a capacitor coupled to the current signal generator, coupled to the first sample and hold and voltage to current conversion components by the second switch and A second sample and hold and voltage to current conversion component is coupled to the signal amplification and voltage to current conversion components by a third switch. The capacitor is configured to generate a voltage signal. Moreover, the system includes a comparator configured to process information associated with the voltage signal and the sensed signal and to generate a comparison signal based on at least information associated with the voltage signal and the sensed signal. Additionally, the system includes a modulation signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the first switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the first switch and a demagnetization period for demagnetization processing. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For each cycle of one or more switching cycles, the first current signal and the second current signal are configured to discharge or charge the capacitor only during the demagnetization period; the third current signal is configured to only be during the on time period The capacitor is discharged or charged; and the fourth current signal is configured to charge or discharge the capacitor during the switching cycle.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. A sense signal is associated with an inductor current flowing through an inductor coupled to the switch, processing information associated with the sense signal, and generating a first current signal, a second current signal based on at least information associated with the sense signal And a third current signal. Additionally, the method includes: generating a fourth current signal; processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal; and based at least on the first current signal, the second current The information associated with the signal, the third current signal, and the fourth current signal generates a voltage signal from at least a capacitor. Moreover, the method includes: processing information associated with the voltage signal and the sensed signal; generating a comparison signal based on at least information associated with the voltage signal and the sensed signal; receiving at least the comparison signal; and based at least on the associated signal The information produces a modulated signal. Moreover, the method includes receiving a modulated signal; and outputting a drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-period and a demagnetization period. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For each cycle of one or more switching cycles, processing for processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal includes: passing only during the demagnetization period A current signal and a second current signal discharge or charge the capacitor; the capacitor is discharged or charged by the third current signal only during the on period; and the capacitor is charged or discharged by the fourth current signal during the switching period.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a signal amplification and voltage to current conversion component configured to receive at least a sensing signal and generate a first current signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch. Additionally, the system includes a current signal generator configured to generate a second current signal, and a capacitor coupled to the current signal generator and coupled to the signal amplification and voltage to current conversion components by the second switch. The capacitor is configured to generate a voltage signal. Additionally, the system includes a comparator configured to process information associated with the voltage signal and the sensed signal and to generate a comparison signal based on at least information associated with the voltage signal and the sensed signal; a modulated signal generator configured Receiving at least a comparison signal and generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the first switch. The drive signal is associated with at least one or more switching cycles, and the first current signal represents an inductor current. Each cycle of one or more switching cycles includes at least an on-time period of the first switch. For each cycle of one or more switching cycles, the first current signal is configured to discharge or charge the capacitor only during the on-time period; and the second current signal is configured to charge the capacitor only during the on-time period Or discharge.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first current signal based on at least information associated with the sensed signal; generating a second current signal; processing associated with the first current signal and the second current signal The associated information; and based on at least information associated with the first current signal and the second current signal, the voltage signal is generated by at least a capacitor. Moreover, the method includes: processing information associated with the voltage signal and the sensing signal; generating a comparison signal based on at least information associated with the voltage signal and the sensing signal; receiving at least the comparison signal; based at least on information associated with the comparison signal Generating a modulation signal; receiving a modulation signal; and outputting a drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least one or more switching cycles, and the first current signal represents an inductor current. Each cycle of one or more switching cycles includes at least an on time period. For each cycle of one or more switching cycles, processing for processing information associated with the first current signal and the second current signal includes discharging or charging the capacitor by the first current signal only during the on-time period And charging or discharging the capacitor by the second current signal only during the on-time period.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a transconductance amplifier configured to receive a sense signal and also receive a predetermined voltage signal through the first switch. The sense signal is associated with an inductor current flowing through an inductor coupled to the second switch, and the transconductance amplifier is further configured to generate a current signal. Additionally, the system includes a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal, and a comparator configured to process information associated with the voltage signal and the sense signal and based at least on the voltage signal and the sense The information associated with the signal produces a comparison signal. Additionally, the system includes a modulation signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the second switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the second switch. The transconductance amplifier is also configured to receive at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. The current signal is configured to charge or discharge the capacitor.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; and processing information associated with the current signal. Moreover, the method includes: generating a voltage signal from at least a capacitor based on at least information associated with the current signal; processing information associated with the voltage signal and the sensing signal; and based at least on the voltage signal and the sensing signal The information produces a comparison signal. Moreover, the method includes: receiving at least a comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting the drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on time period. The process for receiving at least the sensed signal includes receiving at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. Moreover, the processing for processing information associated with the current signal includes charging or discharging the capacitor by the current signal.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a first sample and hold and voltage to current conversion component configured to receive at least a sensed signal and generate a first Current signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch. Additionally, the system includes a second sample and hold and voltage to current conversion component configured to receive at least the sensed signal and generate a second current signal; a signal amplification and voltage to current conversion component configured to receive at least the sensed signal And generating a third current signal; a current signal generator configured to generate a fourth current signal; and a capacitor coupled to the current signal generator, coupled to the first sample and hold and voltage to current conversion component by the second switch And a second sample and hold and voltage to current conversion component, and coupled to the signal amplification and voltage to current conversion components by the third switch, the capacitor being configured to generate the first voltage signal. Moreover, the system includes a multiplier component configured to process information associated with the first voltage signal and the second voltage signal and to generate a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal. Moreover, the system includes a comparator configured to receive the multiplication signal and the sense signal and to generate a comparison signal based on at least information associated with the multiply signal and the sense signal; the modulation signal generator configured to receive at least the comparison And generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the first switch. The drive signal is associated with at least a plurality of switching cycles, and each of the plurality of switching cycles includes at least an on-period of the first switch and a demagnetization period for the demagnetization process. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For a plurality of switching cycles, the first current signal and the second current signal are configured to discharge or charge the capacitor only during the demagnetization period; the third current signal is configured to discharge or charge the capacitor only during the on-time period; The fourth current signal is configured to charge or discharge the capacitor during the switching cycle.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes processing information associated with the sensed signal; and generating the first current signal, the second current signal, and the third current signal based on at least information associated with the sensed signal. Additionally, the method includes: generating a fourth current signal; processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal; and based at least on the first current signal, the second current The information associated with the signal, the third current signal, and the fourth current signal generates a first voltage signal from at least a capacitor. Moreover, the method includes: processing information associated with the first voltage signal and the second voltage signal; generating a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal; receiving the multiplication signal and the sensing signal; And generating a comparison signal based on at least information associated with the multiplication signal and the sensed signal. Additionally, the method includes: receiving at least a comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting the drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least a plurality of switching cycles, and each of the plurality of switching cycles includes at least an on-period and a demagnetization period. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For each of the plurality of switching cycles, processing for processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal includes: passing the first current only during the demagnetization period The signal and the second current signal discharge or charge the capacitor; the capacitor is discharged or charged by the third current signal only during the on-time period; and the capacitor is charged or discharged by the fourth current signal during the switching period.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a transconductance amplifier configured to receive a sense signal and also receive a predetermined voltage signal through the first switch. The sense signal is associated with an inductor current flowing through an inductor coupled to the second switch, the transconductance amplifier being further configured to generate a current signal. Additionally, the system includes a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal, and a comparator configured to process information associated with the voltage signal and the ramp signal and based at least on the voltage signal and the ramp signal The associated information produces a comparison signal. Additionally, the system includes a modulation signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the second switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the second switch. The transconductance amplifier is also configured to receive at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. The current signal is configured to charge or discharge the capacitor.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing information associated with the current signal; and based at least on The information associated with the current signal produces a voltage signal from at least a capacitor. Moreover, the method includes: processing information associated with the voltage signal and the ramp signal; generating a comparison signal based on at least information associated with the voltage signal and the ramp signal; receiving at least the comparison signal; and generating at least based on information associated with the comparison signal Modulate the signal. Moreover, the method includes receiving a modulated signal; and outputting a drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on time period. The process for receiving at least the sensed signal includes receiving at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles; and processing for processing information associated with the current signal includes The capacitor is charged or discharged by a current signal.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a transconductance amplifier configured to receive a sense signal and also receive a predetermined voltage signal through the first switch. The sense signal is associated with an inductor current flowing through an inductor coupled to the second switch, and the transconductance amplifier is further configured to generate a current signal. Additionally, the system includes a capacitor coupled to the transconductance amplifier and configured to generate a first voltage signal, and a multiplier component configured to process information associated with the first voltage signal and the second voltage signal, and at least A multiplication signal is generated based on information associated with the first voltage signal and the second voltage signal. Additionally, the system includes a comparator configured to receive the multiply and sense signals and generate a comparison signal based on at least information associated with the multiply signal and the sense signal signal; the modulation signal generator configured to receive at least the comparison And generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the second switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the second switch. The transconductance amplifier is also configured to receive at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. The current signal is configured to charge or discharge the capacitor.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing information associated with the current signal; and based at least on The information associated with the current signal produces a first voltage signal from at least a capacitor. Moreover, the method includes: processing information associated with the first voltage signal and the second voltage signal; generating a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal; receiving the multiplication signal and the sensing signal; And generating a comparison signal based on at least information associated with the multiplication signal and the sensed signal. Moreover, the method includes: receiving at least a comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting the drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on time period. The process for receiving at least the sensed signal includes receiving at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles; and processing for processing information associated with the current signal includes The capacitor is charged or discharged by a current signal.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes includes a first signal processing component configured to receive at least a sensing signal and generate a first signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the system includes: a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and to generate a third signal; a comparator configured to process The three signals are associated with the sensed signal and the comparison signal is generated based at least on information associated with the third signal and the sensed signal. Additionally, the system includes a signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for the demagnetization process. The first signal processing component is further configured to: for each cycle of the one or more switching cycles, sample the sensed signal at the middle of the on-time period; maintain a sample of the inductor current at the middle of the on-time period a sensed signal; and generating a first signal indicative of a sum of the first multiplication result and the second multiplication result based at least on information associated with the sampled and held sensed signal. For each cycle of one or more switching cycles, the second signal represents the switching period multiplied by a predetermined current magnitude. The integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles; and the third signal represents the integrated cycle-by-cycle accumulated difference. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal Information associated with the second signal; and generating a third signal based on at least information associated with the first signal and the second signal. Moreover, the method includes: processing information associated with the third signal and the sensing signal; generating a comparison signal based on at least information associated with the third signal and the sensing signal; receiving at least the comparison signal; and based at least on the comparison signal The associated information produces a modulated signal. Moreover, the method includes receiving a modulated signal; and outputting a drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for demagnetization processing; for processing associated with the sensed signal The processing of the information includes: sampling the sensing signal in the middle of the on-time period for each cycle of the one or more switching cycles; and maintaining a sense of the inductor current sampleed in the middle of the on-time period Measuring signal. For each of the one or more switching cycles, a first signal generated based on at least information associated with the sensed signal that is sampled and held represents a sum of the first multiplication result and the second multiplication result; and the second signal representation The switching period is multiplied by the predetermined current magnitude. Processing for processing information associated with the first signal and the second signal includes integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles; and the third signal representing the integration The cycle-by-cycle cumulative difference. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

One or more benefits may be obtained depending on the embodiment. These and other additional objects, features and advantages of the present invention will be fully understood from the description and appended claims.

The present invention relates to an integrated circuit. More specifically, the present invention provides illumination systems and methods for constant current control in various modes of operation. Merely by way of example, the invention has been applied to one or more light emitting diodes. However, it will be appreciated that the invention has a broader range of applications.

FIG. 2 is a simplified diagram showing the operational mechanism of illumination system 100 operating in discontinuous conduction mode (DCM). Waveform 210 represents the voltage (e.g., V _DS ) between terminals 122 and 124 as a function of time, waveform 220 represents the current flowing through inductor 140 (e.g., I _L ) as a function of time, and waveform 230 is represented as A current sense signal 114 (eg, V _CS ) as a function of time.

For example, when power switch 120 is turned "on" (eg, during _Ton ), inductor 140 is magnetized and current flowing through inductor 140 (eg, I _L ) flows through power switch 120 and sense resistor 160. The sense resistor 160 converts the inductor current (eg, I _L ) to a current sense signal 114 (eg, V _CS ). In another example, when the power switch 120 is turned off (eg, during T _off ), the inductor 140 is demagnetized and the inductor current (eg, I _L ) flows through the diode 130 , the capacitor 150 , and one or more LED 190. In yet another example, the lamp current 192 (eg, output current) (eg, I _LED ) flowing through one or more of the LEDs 190 is equal to the average of the inductor current (eg, the average of I _L ). If the average value of the inductor current is adjusted to a predetermined level, the lamp current 192 is also adjusted to the predetermined level. Accordingly, the lamp current 192 can be estimated by sensing the inductor current (eg, I _L ) through the sense resistor 160 and calculating the turn-on time (eg, _Ton ) of the power switch 120 .

As noted above, illumination system 100 attempts to control lamp current 192 by controlling the peak magnitude of the inductor current (e.g., I _L ). The lamp current 192 is equal to the average of the inductor current, but the relationship between the average of the inductor current and the peak magnitude of the inductor current depends on the input AC voltage (eg, VAC). For example, if conventional illumination system 100 operates at a fixed switching frequency in continuous conduction mode (CCM) or discontinuous conduction mode (DCM), the on-time should be reduced as the input AC voltage (eg, VAC) increases. Small to control the peak value of the inductor current. As a result, the average of the inductor current and the lamp current 192 also decrease as the input AC voltage increases. Therefore, the lamp current 192 does not remain constant with respect to various input AC voltages.

Figure 3 is a simplified diagram showing an LED illumination system in accordance with one embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 300 includes a pulse width modulation (PWM) controller 310, a switch 320, a diode 330, an inductor 340, capacitors 350 and 352, a sense resistor 360, and a capacitor 364.

For example, switch 320, diode 330, inductor 340, capacitor 350, and sense resistor 360 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, switch 320 is a MOS transistor. In yet another example, the switch 320 is a bipolar transistor (eg, an NPN bipolar transistor). In yet another example, the switch 320 is an insulated gate bipolar transistor (IGBT).

In one embodiment, PWM controller 310 includes constant current control component 380, demagnetization component 382, overcurrent protection (OCP) component 384, clock generator 386, reference signal generator 388, logic component 362, flip-flop component 394, Drive component 396 and rising edge obscuring component 308. In another embodiment, the PWM controller includes terminals 372, 374, 376, 378, and 379.

As shown in FIG. 3, illumination system 300 receives input voltage 332 and provides lamp current 392 (eg, output current) and lamp voltage to one or more LEDs 390. For example, PWM controller 310 outputs drive signal 312 to switch 320 via terminal 372. In another example, drive signal 312 corresponds to a switching period (eg, T _s ). According to one embodiment, if switch 320 is turned "on" (eg, during _Ton ), the current flowing through inductor 340 (eg, I _L ) is sensed by sense resistor 360 and, therefore, protected by overcurrent ( OCP) component 384 receives current sense signal 314 (eg, V _cs ) via terminal 374 and rising edge blanking component 308. For example, in response, over current protection (OCP) component 384 generates control signal 385.

According to another embodiment, the demagnetization component 382 receives the signal 354 from the capacitor 352 via terminal 376 and, in response, generates a demagnetization signal 383. According to yet another embodiment, clock generator 386 generates a clock signal 387, and reference signal generator 388 generates a reference voltage signal 381 (eg, V _REF ) and a reference current signal 389 (eg, I _REF ).

In one embodiment, drive signal 312, current sense signal 314, demagnetization signal 383, clock signal 387, and reference current signal 389 are received by constant current control component 380 that is coupled (eg, via terminal 378) to capacitor 364. For example, in response, constant current control component 380 outputs control signal 391 to logic component 362. In another example, logic component 362 receives control signals 391 and 385 and outputs logic signal 393. In another embodiment, logic signal 393 is received by flip-flop component 394, which also receives clock signal 387 and produces a modulated signal 395. For example, modulation signal 395 is received by drive component 396. In another example, the drive component 396 generates the drive signal 312 based at least on the modulated signal 395.

According to some embodiments, the illumination system 300 can be adjusted to flow through one or more LEDs in various modes of operation, such as in discontinuous conduction mode (DCM), continuous conduction mode (CCM), and/or critical conduction mode (CRM). A lamp current 392 of 390 (eg, I _LED ). For example, lamp current 392 is maintained at a constant level regardless of lamp voltage, inductance of inductor 340, and/or input voltage 332.

4A, 4B, and 4C are simplified diagrams showing timing diagrams of illumination system 300 operating in discontinuous conduction mode (DCM), continuous conduction mode (CCM), and critical conduction mode (CRM), respectively. .

As shown in FIG. 4A, in the DCM, the off time _{Toff of the} switch 320 is much longer than the demagnetization period T _demag . The demagnetization process ends at point C, and the next switching cycle begins after the demagnetization process is completed. The demagnetization period is determined as follows:

Where V _o represents the lamp voltage across one or more of the LEDs 390 and I _{L — p} represents the peak magnitude of the inductor current (eg, I _L ) at the end of the on-time of the switch 320 . In addition, L represents the inductance of the inductor 340. Further, as shown in FIG. 4A, I _{L_0} represents the initial magnitude of the inductor current (eg, I _L ) at the beginning of the on-time of the switch 320 and is equal to zero.

In DCM, the lamp current 392 equals the average inductor current is as follows:

Where I _out represents the lamp current 392 and _Ton represents the on time of the switch 320.

As shown in FIG. 4B, in the CCM, the next switching cycle starts before the demagnetization process is completed. The off time T _{off of the} switch 320 is shorter than the demagnetization period T _demag . In CCM, the lamp current 392 equal to the average inductor current is determined as follows:

As shown in FIG. 4C, in the CRM, the demagnetization period T _{demag is} slightly shorter than the off time T _{off of the} switch. The demagnetization process ends at point C, and the next switching cycle begins shortly after the demagnetization process is completed. The next switching cycle begins at a minimum voltage level (eg, a valley) of the drain voltage of the MOS transistor switch or at a minimum voltage level (eg, a valley) of the collector voltage of the bipolar transistor switch.

In CRM, the lamp current 392 equal to the average inductor current is determined as follows:

Since the demagnetization period T _{demag is} approximately equal to the off time T _{off of the} switch 320, and the initial magnitude of the inductor current (eg, I _L ) at the beginning of the on time of the switch 320 is equal to zero,

Referring to Figure 3, the lamp current 392 is the average size of the inductor current (e.g., I _L ) in each switching cycle, as follows:

Where T represents the integration period and I _L represents the inductor current flowing through the inductor 340. For example, T is equal to or greater than T _s indicating the switching period.

According to one embodiment, will be obtained

I _out = I _c (Equation 7)

The following equation can be obtained by Equation 6:

Where I _c represents a constant current magnitude.

In another embodiment, in practice, if

Where C is a predetermined threshold, a constant lamp current 392 can be obtained or substantially obtained.

Referring to FIGS. 4A, 4B, and 4C, as described above, for DCM, CCM, and CRM, the lamp current 392 is determined according to Equation 2, Equation 3, and Equation 4, respectively. In addition, for CCM and CRM,

In addition, referring to FIG. 3, the inductor current I _L during the on-time of the switch 320 as shown in Equation 10 is converted by the sense resistor 360 into a current sense signal 314, which is sensed by the PWM controller. 310 is received via terminal 374.

According to another example, for DCM, CCM, and CRM,

( I _{L_p} ( i )+ I _{L _0} ( i ))×( T _demag ( i )+ T _on ( i ))= I _c ( i )× T _s ( i ) (Equation 11A)

Or (2 × I _{L_Ton /2} ( i )) × ( T _demag ( i ) + T _on ( i )) = I _c ( i ) × T _s ( i ) (Equation 11B)

Where i corresponds to the ith switching period. In addition, I _{L _ T on / 2} represents the magnitude of the inductor current (eg, I _L ) at the middle of the switch 320 turn-on time.

Furthermore, since the next switching cycle starts in the CCM before the demagnetization process is completed, the actual length of the demagnetization process before the start of the next switching cycle is limited to the off time of the switch; therefore, T _off can be represented by T _demag in the CCM.

For example, if

Or Limit _{N →∞} | (2× I _{L_Ton /2} ( i ))×( T _demag ( i )+ T _on ( i ))- I _c ( i ) × T _s ( i ) |< C (Equation 12B)

Where C is a predetermined threshold, a constant lamp current can be obtained.

In another example, Equation 12A is written as an integral form as follows:

Where U(t) is a unit step function and I _c (t) is equal to the constant I _{c — ref} . Therefore, in the steady state, the following equation can be obtained:

In yet another example, Equation 12B can be written in an integral form, and thus, in a steady state, the following equation can be obtained:

|∫[2× I _{L_Ton /2} ]×[ U ( t - T _s ( i ))- U ( t - T _s ( i )- T _demag ( i ))] dt -∫ I _{c_ref} dt |< C ( Equation 14B)

In one embodiment, with reference to Equations 2, 3, and 4, for DCM, CCM, and CRM,

Where, for CCM, T _demag represents T _off , and for DCM and CRM, I _{L_0 is} equal to zero.

For example, if the lamp current 392 is maintained at a constant level, for example

Then ( I _{L _ p} + I _{L _0} )× = I _ref (Equation 17)

Where I _ref represents a constant current level. therefore,

( I _{L_p} + I _{L _0} )×( T _demag + T _on )= I _ref × T _s (Equation 18)

In another example, T _s , T _demag and _Ton may vary for each switching cycle, so for the ith switching cycle, the following equation can be obtained:

( I _{L_p} ( i )+ I _{L _0} ( i ))×( T _demag ( i )+ T _on ( i ))≠ I _ref × T _s ( i ) (Equation 19)

but if

Limit _{N →∞} |[ ( I _{L_p} ( i )+ I _{L _0} ( i ))×( T _demag ( i )+ T _on ( i ))- I _ref × T _s ( i )]|< A (Equation 20A)

Where A represents a predetermined threshold, the following form of integration can be obtained:

Where U(t) is the unit step function.

In yet another example,

Limit _{N →∞} |[ (2× I _{L_Ton /2} ( i ))×( T _demag ( i )+ T _on ( i ))- I _ref × T _s ( i )]|< A (Equation 20B)

Where A represents a predetermined threshold, the following form of integration can be obtained:

Where U(t) is the unit step function.

According to yet another embodiment, if equations 20A and 21A are satisfied and/or equations 20B and 21B are satisfied, lamp current 392 is maintained at a constant level regardless of lamp voltage, inductance of inductor 340, and/or input voltage 332.

For example, referring to FIG. 3, when switch 320 is turned "on" (eg, during _Ton ), current flowing through inductor 340 (eg, I _L ) is sensed by sense resistor 360, which senses the resistor 360 produces a current sense signal 314 (eg, V _cs ) as follows:

V _cs = I _L × R _s (Equation 22)

Wherein, V _cs represents the current sense signal 314, I _L represents the current flowing through the inductor 340, and R _s represents the resistance of the sense resistor 360.

In another example, based on Equation 21(A) and Equation 22, the following equation can be obtained:

Where V _{cs — p} represents the peak magnitude of the current sense signal 314 and corresponds to the peak magnitude of the inductor current at the end of the on time of the switch 320 . Additionally, V _{cs_0} represents the initial magnitude of current sense signal 314 and corresponds to the initial magnitude of the inductor current at the beginning of the on time of switch 320.

In yet another example, based on Equation 21(B) and Equation 22, the following equation can be obtained:

Where V _{cs_Ton /2} represents the _{magnitude of} current sense signal 314 at the middle of the switch-on time of switch 320.

As discussed above and further emphasized herein, FIG. 3 is merely an example, which should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Fig. 3 is realized according to Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, and/or Fig. 12. In another example, rising edge blanking component 308 is removed and current sense signal 314 (eg, V _cs ) is received by overcurrent protection (OCP) component 384 via terminal 374 without passing through rising edge blanking component 308.

Figure 5 is a simplified diagram of an LED illumination system in accordance with another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 500 includes a switch 420, a diode 430, an inductor 440, capacitors 450 and 452, and a sense resistor 460. In addition, the illumination system 500 further includes cycle-by-cycle processing components 520 and 522, a capacitor 530, a signal conditioning component 533, a transconductance amplifier 540, a comparator 542, a demagnetization detection component 544, and a rising edge blanking component. 550. A flip-flop component 554, a clock generator 556, and a driver component 558.

For example, switch 420, diode 430, inductor 440, capacitor 450, and sense resistor 460 are distributed identically to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160. In another example, cycle-by-cycle processing components 520 and 522, signal conditioning component 533, transconductance amplifier 540, comparator 542, demagnetization detection component 544, rising edge obscuration component 550, flip-flop component 554, clock generator 556, and Driver assembly 558 is located on wafer 510. In yet another example, capacitor 530 is located outside of wafer 510. In yet another example, wafer 510 includes terminals 512, 514, 516, 518, and 519.

As shown in FIG. 5, illumination system 500 receives input voltage 532 and provides lamp current 592 (eg, output current) and lamp voltage to one or more LEDs 590. According to one embodiment, during the on time (eg, _Ton ) of switch 420, the current flowing through inductor 440 and switch 420 is sensed by resistor 460. For example, resistor 460 generates a current sense signal 552 through terminal 514 and with rising edge blanking component 550. In another example, during the on time (eg, _Ton ) of switch 420, current sense signal 552 is as follows:

V _cs = I _L × R _s (Equation 24)

Where V _cs represents the current sense signal 552, I _L represents the current flowing through the inductor 440, and R _s represents the resistance of the resistor 460.

In yet another example, combining Equation 20A and Equation 24, the following equation is obtained:

Where A represents a predetermined threshold and I _ref represents a predetermined reference current. In addition, V _{cs — p} represents the peak magnitude of the current sense signal 552 , which corresponds, for example, to the peak magnitude of the inductor current at the end of the on-time of the switch 420 . Furthermore, V _{cs_0} represents the initial magnitude of the current sense signal 552, which corresponds, for example, to the initial magnitude of the inductor current at the beginning of the on time of the switch 420. Moreover, T _s represents the switching period of the switch 420, and T _on represents the on-time of the switch 420. In addition, for DCM and CRM, T _demag represents the demagnetization period, and for CCM, T _demag represents the off time of the switch 420 (eg, T _off ).

In yet another example, combining 20B and Equation 24, the following equation is obtained:

Where A represents a predetermined threshold and I _ref represents a predetermined reference current. In addition, V _{cs — Ton / 2} represents the magnitude of the current sense signal 552 at the middle of the turn-on time of the switch 420. Also, T _s represents the switching period of the switch 420, and T _on represents the on-time of the switch 420. In addition, for DCM and CRM, T _demag represents the demagnetization period, and for CCM, T _demag represents the off time of the switch 420 (eg, T _off ).

Current sense signal 552 is received by cycle-by-cycle processing component 520, in accordance with some embodiments. In one embodiment, cycle-by-cycle processing component 520 generates a signal 521 equal to ( I _{L _ p} + I _{L _ 0} ) × ( T _on + T _demag ) for each switching cycle. In another embodiment, for each switching cycle, the cycle-by-cycle processing component 520 produces equal to ( I _{L _ p} + I _{L _ 0} ) × ( T _on ) + (2 × I _{L _ Ton / 2} ) × ( T _Demag ) signal 521.

For example, for each switching cycle, when switch 420 is closed, the average inductor current during the on time (eg, _Ton ) of switch 420 is directly determined based on sensed current 552 as ( I _{L_p} + I _{L _ 0} ). In another example, for each switching cycle, the average inductor current during the demagnetization period (eg, T _demag ) is indirectly determined to be I _{L _ Ton/} based on the current 552 sensed in the middle of the on-time. ₂ , I _{L _ Ton /2} is sampled when switch 420 is closed and then held by cycle-by-cycle processing component 520. In yet another example, for each switching cycle, the average inductor current during the off time (eg, _Toff ) is determined indirectly based on the current 552 sensed in the middle of the on time ( I _{L _ Ton /2} ) × ( T _demag ) / ( T _{o ff} ), and I _{L _ Ton / 2} is sampled when the switch 420 is closed and then held by the cycle-by-cycle processing component 520. According to certain embodiments, for DCM and CRM, the demagnetization period (eg, T _demag ) represents the duration of the demagnetization process, but for CCM, the demagnetization period (eg, T _demag ) represents the duration of the off time.

In yet another example, for each switching cycle, processing component 522 generates a signal 523 equal to I _ref × T _s . In yet another example, the demagnetization detection component 544 receives the feedback signal 551 from the capacitor 452 and generates a Demag signal 545. For each switching cycle, the Demag signal 545 has a pulse width T _demag .

According to another embodiment, signals 523 and 521 are received by transconductance amplifier 540. For example, the transconductance amplifier 540 and the capacitor 530, which are part of the actual implementation of the equation 25A, amplify and integrate the size difference I _ref × T _s -( I _{L_p} + I _{L _ 0} ) × ( T _on + T _demag ) . In another example, the size difference I _ref × T _s - is determined by the transconductance amplifier 540 and the capacitor 530 as part of the actual implementation of the equation 25B. ( I _{L _ p} + I _{L _ 0} )×( T _on )+(2× I _{L _ Ton / 2} )×( T _demag ) Zoom in and integrate. In another example, transconductance amplifier 540 and capacitor 530 form an integrator that produces signal 531 that is received directly by comparator 542 or indirectly through signal conditioning component 533.

According to yet another embodiment, the comparator 542 also receives the current sense signal 552 and in response generates a comparison signal 543. For example, comparison signal 543 is received by flip-flop component 554, and flip-flop component 554 also receives clock signal 555 from clock generator 556 and produces modulation signal 557. In another example, the modulation signal 557 is received by the driver component 558, which in response generates a drive signal 559.

In one embodiment, drive signal 559 is sent to switch 420 through terminal 512 and is also received by cycle-by-cycle processing component 520. In another embodiment, signal 531 is used to adjust the pulse width of drive signal 559 by pulse width modulation.

As discussed above and further emphasized herein, FIG. 5 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, signal conditioning component 533 is removed and signal 531 is directly received by comparator 542. In another example, the rising edge blanking component 550 is removed and the signal 552 is received directly from the terminal 514. In yet another example, capacitor 530 is located on wafer 510. In yet another example, for CRM, clock generator 556 is replaced by a pulse signal generator that receives Demag signal 545 and in response generates a pulse of pulse signal 555. In yet another example, pulse signal 555 is received by flip-flop component 554, and different pulses of pulse signal 555 correspond to different switching cycles.

Figure 6 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 600 includes a switch 4620, a diode 4630, an inductor 4640, capacitors 4650 and 4652, and a sense resistor 4660. Additionally, the illumination system 600 further includes a comparator 642, a demagnetization detection component 644, a rising edge blanking component 650, a flip-flop component 654, a clock generator 656, and a driver component 658. In addition, the illumination system 600 also includes sample and hold components 662 and 664, voltage to current converters 660, 666 and 668, switch 680 and capacitor 690. In addition, illumination system 600 also includes a signal amplifier 686, a voltage to current converter 688, and a switch 682.

For example, switch 4620, diode 4630, inductor 4640, capacitor 4650, and sense resistor 4660 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 642, demagnetization detection component 644, rising edge obscuration component 650, flip-flop component 654, clock generator 656 and driver component 658, sample and hold components 662 and 664,, voltage to current converter 660 666 and 668, switch 680, signal amplifier 686, voltage to current converter 688, and switch 682 are located on wafer 610. In yet another example, capacitor 690 is located outside of wafer 610. In yet another example, wafer 610 includes terminals 612, 614, 616, 618, and 619.

According to one embodiment, in the CCM, the next switching cycle begins before the demagnetization process is completed. For example, the actual length of the demagnetization process (eg, T _demag ) before the start of the next switching cycle is limited to the off time of the switch 4620 (eg, T _off ); therefore, T _off can be represented by T _demag in the CCM. According to another embodiment, in the DCM, the off time (eg, _Toff ) of the switch 4620 is much longer than the demagnetization period (eg, T _demag ). According to yet another embodiment, in CRM, the off time (eg, _Toff ) of switch 4620 is slightly longer than the demagnetization period (eg, T _demag ).

As shown in FIG. 6, illumination system 600 receives input voltage 632 and provides lamp current 692 (eg, output current) and lamp voltage to one or more LEDs 4690. In one embodiment, the current flowing through inductor 4640 is sensed by resistor 4660. For example, resistor 4660 passes through terminal 614 and produces a current sense signal 652 along with rising edge blanking component 650.

In another embodiment, the sample and hold component 662 receives at least the drive signal 659 and the control signal 661. For example, control signal 661 includes a pulse having a rising edge at the beginning of the on time of switch 4620 (eg, at the rising edge of drive signal 659) for each switching cycle. In another example, during this pulse, current sense signal 652 (eg, V _cs ) is sampled and held as voltage signal 663 (eg, V _s2 ). In yet another example, after the falling edge of the pulse, voltage signal 663 remains constant (eg, equal to V _{cs — 0} ) until the next pulse of control signal 661 . In one embodiment, the pulse of control signal 661 is so narrow that V _{cs — 0 is} approximately equal to current sense signal 652 at the beginning of switch 4620's turn-on time and thus represents the current sense signal 652 at the beginning of switch 4620's turn-on time.

In yet another embodiment, the sample and hold component 664 receives at least a drive signal 659 that includes a pulse having a width corresponding to a switch-on time (eg, _Ton ) for each switch cycle. For example, during a pulse of drive signal 659, current sense signal 652 (eg, V _cs ) is sampled and held as voltage signal 665 (eg, V _s3 ). In yet another example, after the falling edge of the pulse, the voltage signal 665 remains constant (eg, equal to V _{cs — p} ) until the next pulse of the drive signal 659 .

According to one embodiment, as shown in FIG. 6, voltage signals 663 and 665 are received by voltage to current converters 666 and 668, which in response generate current signals 667 and 669, respectively. For example, current signal 667 is represented by I _s2 and current signal 669 is represented by I _s3 . In another example, the sum of current signals 667 and 669 forms a sinking current 681 (eg, I _sink2 ) that is used to discharge capacitor 690 if switch 680 is closed.

According to another embodiment, the switch 680 is controlled by a Demag signal 645 generated by the demagnetization detection component 644. For example, if the Demag signal 645 is at a logic high level, the switch 680 is closed. In another example, switch 680 is closed during the demagnetization period and is open during the remainder of the switching period. In yet another example, the discharge current 681 discharges the capacitor 690 during the demagnetization period (eg, during T _demag ).

Moreover, according to one embodiment, as shown in FIG. 6, signal amplifier 686 receives current sense signal 652 and generates voltage signal 687 (eg, _Vs1 ). For example, the magnitude of voltage signal 687 (eg, V _s1 ) is equal to twice the current sense signal 652 (eg, V _cs ). According to another embodiment, voltage signal 687 is received by voltage to current converter 688, which in response generates a discharge current 689 (eg, I _sink1 ). For example, if switch 682 is closed, discharge current 689 is used to discharge capacitor 690.

According to yet another embodiment, the switch 682 is controlled by a signal 685 generated based on the signal 659. For example, if signal 685 is at a logic high level, switch 682 is closed, and if signal 685 is at a logic low level, switch 682 is open. In another example, switch 682 is closed during the on time of switch 4620 and is off during the off time of switch 4620. In yet another example, the discharge current 689 discharges the capacitor 690 during the on time of the switch 4620. According to yet another embodiment, voltage to current converter 660 receives a predetermined voltage signal 691 (eg, V _ref ) and in response generates a charging current 661 (eg, I _ref ). For example, the charging current 661 during the switching period (e.g., during the T _s) to charge the capacitor 690. According to yet another embodiment, signal 683 (eg, V _C ) is generated by charge current 661 (eg, I _ref ), discharge current 681 (eg, I _{sink 2} ), and discharge current 689 (eg, I _sink1 ) for capacitor 690 . For example, the magnitude of signal 683 (eg, V _C ) decreases during the demagnetization period (eg, during T _demag ) and increases during the remainder of the switching period.

In one embodiment, comparator 642 receives signal 683 (eg, V _C ) and also receives current sense signal 652 through slope compensation component 684 . For example, in response, comparator 642 produces a comparison signal 643 that is received by flip-flop component 654. In another example, flip-flop component 654 also receives clock signal 655 from clock generator 656 and produces a modulated signal 657. In yet another example, the modulated signal 657 is received by the driver component 658 and the driver component 658 in response outputs a drive signal 659 to the switch 4620 and the sample and hold components 662 and 664.

According to one embodiment, for CCM, DCM, and CRM,

I _{s 2} = α × V _{cs_ 0} = α × I _{L_ 0} × R _s (Equation 26)

And I _{s 3} = α × V _{cs_p} = α × I _{L_p} × R _s (Equation 27)

Therefore, I _{sin k 2} = I _{s 2} + I _{s 3} = α × I _{L_ 0} × R _s + α × I _{L _ p} × R _s (Equation 28)

In addition, I _{sin k 1} = 2 × α × V _cs (Equation 29)

Where α is a constant associated with voltage to current converters 666, 668, and 688, and R _s is the resistance of sense resistor 4660.

According to another embodiment, if the charging and discharging of capacitor 690 are equal during each switching cycle, then illumination system 600 reaches equilibrium (eg, steady state) as follows:

Where I _{sin k 1_ p} = 2 × α × V _{cs_p} (Equation 31)

Combining equations 28-31, the following equation can be obtained:

If I _ref = β × V _ref (Equation 33A)

Then ( I _{L _0} + I _{L_p} )× = (Equation 34A)

Where β is a constant associated with voltage to current converter 660.

Because I _out = ×( I _{L_ 0} + I _{L_p} )× (Equation 35A)

Therefore, I _out = × V _ref (Equation 36A)

Where I _out represents the lamp current 692. According to yet another embodiment, α, β, R _s and V _ref are all constants, thus obtaining a constant lamp current 692.

As discussed above and further emphasized herein, FIG. 6 is merely an example, which should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. In one embodiment, the rising edge blanking component 650 is removed and the signal 652 is received directly from the terminal 614. In another embodiment, capacitor 690 is located on wafer 610. In yet another embodiment, a low pass filter and/or buffer is added to process signal 683 before signal 683 is received by comparator 642. For example, a voltage divider (eg, formed of two resistors) is further added to divide the processed signal 683 before the processed signal 683 is received by the comparator 642.

According to another embodiment, for DCM and CRM, _{Vcs_0 is} equal to zero, so if illumination system 600 does not need to operate in CCM for constant lamp current 692, sample and hold component 662 and voltage to current converter 666 are removed. According to yet another embodiment, for CRM, clock generator 656 is replaced by a pulse signal generator that receives Demag signal 645 and in response generates a pulse of pulse signal 655. For example, pulse signal 655 is received by flip-flop component 654, and different pulses of pulse signal 655 correspond to different switching cycles.

According to yet another embodiment, the illumination system 600 is modified such that the following equations can be obtained:

If I _ref = β × V _ref (Equation 33B)

Then (2 × I _{L _ Ton /2} ) × = (Equation 34B)

Where β is a constant associated with voltage to current converter 660.

Since I _out = ( I _{L_Ton /2} ) × (Equation 35B)

Therefore, I _out = × V _ref (Equation 36B)

Where I _out represents the lamp current 692. α, β, R _s and V _ref are all constants, so according to certain embodiments, a constant lamp current 692 is obtained.

Figure 7 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 700 includes a switch 4720, a diode 4730, an inductor 4740, a capacitor 4750, and a sense resistor 4760. Additionally, the illumination system 700 further includes a comparator 742, a rising edge blanking component 750, a flip-flop component 754, a clock generator 756, and a driver component 758. In addition, the illumination system 700 also includes voltage to current converters 760 and 788, switches 780 and 782, capacitor 790, and signal amplifier 786.

For example, switch 4720, diode 4730, inductor 4740, capacitor 4750, and sense resistor 4760 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 742, rising edge blanking component 750, flip-flop component 754, clock generator 756, driver component 758, voltage to current converters 760 and 788, switches 780 and 782, and signal amplifier 786 are located on the wafer. On 710. In yet another example, capacitor 790 is located outside of wafer 710. In yet another example, wafer 710 includes terminals 712, 714, 718, and 719.

As shown in FIG. 7, illumination system 700 receives input voltage 732 and provides lamp current 792 (eg, output current) and lamp voltage to one or more LEDs 4790. In one embodiment, the current flowing through inductor 4740 is sensed by resistor 4760. For example, resistor 4760 passes through terminal 714 and produces a current sense signal 752 along with rising edge blanking component 750.

In another embodiment, signal amplifier 786 receives current sense signal 752 (eg, V _cs ) and generates voltage signal 787 (eg, V _s1 ). For example, the magnitude of voltage signal 787 (eg, V _s1 ) is equal to twice the current sense signal 752 (eg, V _cs ). In another embodiment, the gain of signal amplifier 786 is G (eg, G is a predetermined positive number). In yet another embodiment, voltage signal 787 is received by voltage to current converter 788, which in response generates a discharge current 789 (eg, I _sink1 ). For example, if switch 782 is closed, discharge current 789 is used to discharge capacitor 790. In another example, switch 782 is controlled by signal 785 generated based on drive signal 759.

In yet another embodiment, voltage to current converter 760 receives a predetermined voltage signal 791 (eg, V _ref ) and in response generates a charging current 761 (eg, I _ref ). For example, if switch 780 is closed, charging current 761 charges capacitor 790. In another example, switch 780 is controlled by signal 785 generated based on drive signal 759.

According to one embodiment, if signal 785 is at a logic high level, switches 780 and 782 are closed, and if signal 785 is at a logic low level, switches 780 and 782 are open. For example, switches 780 and 782 are closed during the on time of switch 4720 and are open during the off time of switch 4720. In another example, charging current 761 charges capacitor 790 during the on time of switch 4720, and discharge current 789 discharges capacitor 790. According to another embodiment, signal 783 (eg, V _C ) is generated by a charging current 761 (eg, I _ref ) and a discharging current 789 (eg, I _sink1 ) for capacitor 790 .

As shown in FIG. 7, comparator 742 receives signal 783 (eg, V _C ) and also receives current sense signal 752 through ramp compensation component 784. For example, in response, comparator 742 generates a comparison signal 743 that is received by flip-flop component 754. In another example, flip-flop component 754 also receives clock signal 755 from clock generator 756 and produces a modulated signal 757. In yet another example, the modulated signal 757 is received by the driver component 758, which in response outputs a drive signal 759 to the switch 4720.

According to one embodiment, for CCM, due to

Then I _out = (Equation 38)

Wherein, I _out represents the lamp current 792, and R _s is the resistance of the sensing resistor 4760. According to another embodiment, both R _s and V _ref are constants, thus obtaining a constant lamp current 792.

As discussed above and further emphasized herein, Figure 7 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, rising edge blanking component 750 is removed and signal 752 is received directly from terminal 714. In another example, capacitor 790 is located on wafer 710. In yet another example, a low pass filter and/or buffer is added to process signal 783 before signal 783 is received by comparator 742. In yet another example, two resistors are further added to divide the processed signal 783 before the processed signal 783 is received by the comparator 742.

Figure 8 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 800 includes a switch 4820, a diode 4830, an inductor 4840, a capacitor 4850, and a sense resistor 4860. Additionally, the illumination system 800 further includes a comparator 842, a rising edge blanking component 850, a flip-flop component 854, a clock generator 856, and a driver component 858. In addition, the illumination system 800 also includes a transconductance amplifier 886, switches 880 and 882, and a capacitor 890.

For example, switch 4820, diode 4830, inductor 4840, capacitor 4850, and sense resistor 4860 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 842, rising edge blanking component 850, flip-flop component 854, clock generator 856, driver component 858, transconductance amplifier 886, and switches 880 and 882 are located on wafer 810. In yet another example, capacitor 890 is located outside of wafer 810. In yet another example, wafer 810 includes terminals 812, 814, 818, and 819.

As shown in FIG. 8, illumination system 800 receives input voltage 832 and provides lamp current 892 (eg, output current) and lamp voltage to one or more LEDs 4890. In one embodiment, the current flowing through inductor 4840 is sensed by resistor 4860. For example, resistor 4860 passes through terminal 814 and produces a current sense signal 852 along with rising edge blanking component 850.

In another embodiment, transconductance amplifier 886 receives current sense signal 852 (eg, V _cs ) and also receives a predetermined voltage signal 891 (eg, V _ref ) through switch 880. For example, switch 880 is controlled by signal 885 generated based on drive signal 859. In another example, if signal 885 is at a logic high level, switch 880 is closed, and if signal 885 is at a logic low level, switch 880 is open. In yet another example, switch 880 is closed during the on time of switch 4820 and is off during the off time of switch 4820.

In yet another embodiment, during the on time of switch 4820, transconductance amplifier 886 compares current sense signal 852 (eg, V _cs ) to a predetermined voltage signal 891 (eg, V _ref ) and senses current The difference between the measured signal 852 (eg, V _cs ) and the predetermined voltage signal 891 (eg, V _ref ) is converted to current 889. For example, current 889 is proportional to the difference between current sense signal 852 (eg, V _cs ) and predetermined voltage signal 891 (eg, V _ref ). In another example, during the on time of switch 4820, if the magnitude of predetermined voltage signal 891 (eg, V _ref ) is greater than current sense signal 852 (eg, V _cs ), current 889 charges capacitor 890, and If the magnitude of the predetermined voltage signal 891 (eg, V _ref ) is less than the current sense signal 852 (eg, V _cs ), the capacitor 890 is discharged.

In yet another embodiment, during the off time of switch 4820, predetermined voltage signal 891 (eg, _Vref ) is shorted to ground through switch 882. For example, switch 882 is controlled by signal 845 generated based on drive signal 859. In another example, if signal 845 is at a logic high level, switch 882 is closed, and if signal 845 is at a logic low level, switch 882 is open. In yet another example, switch 882 is closed during the off time of switch 4820 and is off during the on time of switch 4820.

As shown, the signal 883 of FIG. 8 (e.g., V _C) is generated on the capacitor 890 charging and / or discharging current by a 889. In one embodiment, comparator 842 receives signal 883 (eg, V _C ) and also receives current sense signal 852 through slope compensation component 884. For example, in response, comparator 842 generates a comparison signal 843 that is received by flip-flop component 854. In another example, flip-flop component 854 also receives clock signal 855 from clock generator 856 and produces a modulated signal 857. In yet another example, the modulated signal 857 is received by the driver component 858, which in response outputs a drive signal 859 to the switch 4820.

As discussed above and further emphasized herein, FIG. 8 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, rising edge blanking component 850 is removed and signal 852 is received directly from terminal 814. In another example, capacitor 890 is located on wafer 810.

Figure 9 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 900 includes a switch 4920, a diode 4930, an inductor 4940, capacitors 4950 and 4952, and a sense resistor 4960. Additionally, the illumination system 900 further includes a comparator 942, a demagnetization detection component 944, a rising edge blanking component 950, a flip-flop component 954, a pulse signal generator 956, and a driver component 958. In addition, the illumination system 900 also includes a transconductance amplifier 986, switches 980 and 982, and a capacitor 990.

For example, switch 4920, diode 4930, inductor 4940, capacitor 4950, and sense resistor 4960 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 942, demagnetization detection component 944, rising edge blanking component 950, flip-flop component 954, pulse signal generator 956, driver component 958, transconductance amplifier 986, and switches 980 and 982 are located on wafer 910. . In yet another example, capacitor 990 is located outside of wafer 910. In yet another example, wafer 910 includes terminals 912, 914, 916, 918, and 919.

As shown in FIG. 9, illumination system 900 receives input voltage 932 and provides lamp current 992 (eg, output current) and lamp voltage to one or more LEDs 4990. In one embodiment, the current flowing through inductor 4940 is sensed by resistor 4960. For example, resistor 4960 generates a current sense signal 952 through terminal 914 and with rising edge blanking component 950.

In another embodiment, transconductance amplifier 986 receives current sense signal 952 (eg, V _cs ) and also receives a predetermined voltage signal 991 (eg, V _ref ) through switch 980. For example, switch 980 is controlled by signal 985 generated based on drive signal 959. In another example, if signal 985 is at a logic high level, switch 980 is closed, and if signal 985 is at a logic low level, switch 980 is open. In yet another example, switch 980 is closed during the on time of switch 4920 and is off during the off time of switch 4920.

In yet another embodiment, during the on time of switch 4920, transconductance amplifier 986 compares current sense signal 952 (eg, V _cs ) to a predetermined voltage signal 991 (eg, V _rer ) and _senses current The difference between the measured signal 952 (eg, V _cs ) and the predetermined voltage signal 991 (eg, V _ref ) is converted to current 989. For example, current 989 is proportional to the difference between current sense signal 952 (eg, V _cs ) and predetermined voltage signal 991 (eg, V _ref ). In another example, during the on time of switch 4920, if the magnitude of predetermined voltage signal 991 (eg, V _ref ) is greater than current sense signal 952 (eg, V _cs ), current 989 charges capacitor 990, and If the magnitude of the predetermined voltage signal 991 (eg, V _ref ) is less than the current sense signal 952 (eg, V _cs ), the capacitor 990 is discharged.

In yet another embodiment, during the off time of switch 4920, predetermined voltage signal 991 (eg, _Vref ) is shorted to ground through switch 982. For example, switch 982 is controlled by signal 945 generated based on drive signal 959. In another example, if signal 945 is at a logic high level, switch 982 is closed, and if signal 945 is at a logic low level, switch 982 is open. In yet another example, switch 982 is closed during the off time of switch 4920 and is off during the on time of switch 4920.

As shown, the signal 983 (e.g., V _C) of FIG. 9 and 989 generate 990 charge / discharge current of the capacitor or by for. In one embodiment, comparator 942 receives signal 983 (eg, V _C ) and also receives current sense signal 952 . For example, in response, comparator 942 produces a comparison signal 943 that is received by trigger component 954. In another example, trigger component 954 also receives pulse signal 955 from pulse signal generator 956 and produces modulated signal 957. In yet another example, the modulation signal 957 is received by the driver component 958, which in response outputs a drive signal 959 to the switch 4920. In another embodiment, pulse signal generator 956 receives Demag signal 945 from demagnetization detection component 944 and, in response, generates a pulse of pulse signal 955. For example, different pulses of pulse signal 955 correspond to different switching cycles.

As discussed above and further emphasized herein, FIG. 9 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, rising edge masking component 950 is removed and signal 952 is received directly from terminal 914. In another example, capacitor 990 is located on wafer 910. In yet another example, a slope compensation component is added, and the comparator 942 receives the current sense signal 952 through the slope compensation component.

Figure 10 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 1000 includes a switch 5020, a diode 5030, an inductor 5040, capacitors 5050 and 5052, and a sense resistor 5060. Additionally, the illumination system 1000 further includes a comparator 1042, a demagnetization detection component 1044, a rising edge blanking component 1050, a flip-flop component 1054, a clock generator 1056, and a driver component 1058. In addition, the illumination system 1000 also includes sample and hold components 1062 and 1064, voltage to current converters 1060, 1066 and 1068, a switch 1080, and a capacitor 1090. In addition, illumination system 1000 also includes a signal amplifier 1086, a voltage to current converter 1088, a switch 1082, a multiplier assembly 1096, and resistors 1098 and 1099.

For example, switch 5020, diode 5030, inductor 5040, capacitor 5050, and sense resistor 5060 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 1042, demagnetization detection component 1044, rising edge obscuration component 1050, flip-flop component 1054, clock generator 1056, driver component 1058, sample and hold components 1062 and 1064, voltage to current converter 1060 1066 and 1068, switch 1080, signal amplifier 1086, voltage to current converter 1088, switch 1082, and multiplier assembly 1096 are located on wafer 1010. In yet another example, capacitor 1090 is located outside of wafer 1010. In yet another example, wafer 1010 includes terminals 1012, 1014, 1016, 1017, 1018, and 1019.

According to one embodiment, in the CCM, the next switching cycle begins before the demagnetization process is completed. For example, the actual length of the demagnetization process (eg, T _demag ) before the start of the next switching cycle is limited to the off time of the switch 5020 (eg, T _off ); therefore, T _off can be represented by T _demag in the CCM. According to another embodiment, in the DCM, the off time (eg, _Toff ) of the switch 5020 is much longer than the demagnetization period (eg, T _demag ). According to yet another embodiment, in CRM, the off time (eg, _Toff ) of switch 5020 is slightly longer than the demagnetization period (eg, T _demag ).

As shown in FIG. 10, illumination system 1000 receives input voltage 1032 and provides rectified voltage 1093 and lamp current 1092 (eg, output current) to drive one or more LEDs 5090. In one embodiment, the current flowing through inductor 5040 is sensed by resistor 5060. For example, resistor 5060 generates a current sense signal 1052 through terminal 1014 and with rising edge blanking component 1050.

In another embodiment, the sample and hold component 1062 receives at least the drive signal 1059 and the control signal 1061. For example, control signal 1061 includes a pulse having a rising edge at the beginning of the on time of switch 5020 (eg, at the rising edge of drive signal 1059) for each switching cycle. In another example, during this pulse, current sense signal 1052 (eg, V _cs ) is sampled and held as voltage signal 1063 (eg, V _s2 ). In yet another example, after the falling edge of the pulse, voltage signal 1063 remains constant (eg, equal to V _{cs — 0} ) until the next pulse of control signal 1061 . In one embodiment, the pulse of control signal 1061 is so narrow that V _{cs — 0 is} approximately equal to current sense signal 1052 at the beginning of the on time of switch 5020 and thus represents the current sense signal at the beginning of the on time of switch 5020 1052.

In yet another embodiment, the sample and hold component 1064 receives at least a drive signal 1059 that includes a pulse having a width corresponding to a switch-on time (eg, _Ton ) for each switch cycle. For example, during a pulse of drive signal 1059, current sense signal 1052 (eg, V _cs ) is sampled and held as voltage signal 1065 (eg, V _s3 ). In another example, after the falling edge of the pulse, voltage signal 1065 remains constant (eg, equal to V _{cs — p} ) until the next pulse of drive signal 1059.

According to one embodiment, as shown in FIG. 10, voltage signals 1063 and 1065 are received by voltage to current converters 1066 and 1068, and voltage to current converters 1066 and 1068, in response, generate current signals 1067 and 1069, respectively. For example, current signal 1067 is represented by I _s2 and current signal 1069 is represented by I _s3 . In another example, the sum of current signals 1067 and 1069 forms a discharge current 1081 (eg, I _sink2 ) that is used to discharge capacitor 1090 if switch 1080 is closed.

According to another embodiment, the switch 1080 is controlled by a Demag signal 1045 generated by the demagnetization detection component 1044. For example, if the Demag signal 1045 is at a logic high level, the switch 1080 is closed. In another example, switch 1080 is closed during the demagnetization period and is off during the remainder of the switching period. In yet another example, the discharge current 1081 discharges the capacitor 1090 during the demagnetization period (eg, during T _demag ).

Moreover, according to one embodiment, as shown in FIG. 10, signal amplifier 1086 receives current sense signal 1052 and generates voltage signal 1087 (eg, _Vs1 ). For example, voltage signal 1087 (eg, V _s1 ) is equal to twice the current sense signal 1052 (eg, V _cs ). According to another embodiment, voltage signal 1087 is received by voltage to current converter 1088, which in response generates a discharge current 1089 (eg, I _sink1 ). For example, if switch 1082 is closed, discharge current 1089 is used to discharge capacitor 1090.

According to yet another embodiment, the switch 1082 is controlled by a signal 1085 that is generated based on the signal 1059. For example, if signal 1085 is at a logic high level, switch 1082 is closed, and if signal 1085 is at a logic low level, switch 1082 is open. In another example, switch 1082 is closed during the on time of switch 5020 and is off during the off time of switch 5020. In yet another example, the discharge current 1089 discharges the capacitor 1090 during the on time of the switch 5020. According to yet another embodiment, the voltage to current converter 1060 receives a predetermined voltage signal 1091 (eg, V _ref ) and in response generates a charging current 1061 (eg, I _ref ). For example, the charging current 1061 during the switching period (e.g., during the T _s) of the capacitor 1090 is charged. According to yet another embodiment, the signal 1083 (eg, V _C ) is generated by a charging current 1061 (eg, I _ref ), a discharging current 1081 (eg, I _{sink 2} ), and a discharging current 1089 (eg, I _{sink 1} ) for the capacitor 1090 . For example, the magnitude of signal 1083 (eg, V _C ) decreases during the demagnetization period (eg, during T _demag ) and increases during the remainder of the switching period.

As shown in FIG. 10, resistor 1098 receives rectified voltage 1093 and produces a signal 1095 with resistor 1099. For example, signal 1095 is received by multiplier component 1096 through terminal 1017. In another example, multiplier component 1096 also receives signal 1083 (eg, V _C ) and generates control signal 1097 based on at least information associated with signals 1095 and 1083.

In one embodiment, the comparator 1042 receives the control signal 1097 and also receives the current sense signal 1052 through the slope compensation component 1084. For example, in response, comparator 1042 generates a comparison signal 1043 that is received by flip-flop component 1054. In another example, the flip-flop component 1054 also receives a clock signal 1055 from the clock generator 1056 and generates a modulated signal 1057. In yet another example, the modulated signal 1057 is received by the driver assembly 1058, and the driver assembly 1058 in response outputs a drive signal 1059 to the switch 5020 and the sample and hold components 1062 and 1064. In another embodiment, for DCM, CCM, and CRM, illumination system 1000 has a power factor equal to or greater than 0.9 (eg, equal to one). For example, a high power factor and precise control of the constant lamp current 1092 are simultaneously achieved by the illumination system 1000.

In yet another embodiment, if the charging and discharging of capacitor 1090 are equal during a plurality of switching cycles, illumination system 1000 reaches equilibrium (eg, a steady state) as follows:

Where i represents the ith switching period.

As discussed above and further emphasized herein, FIG. 10 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. In one embodiment, the rising edge blanking component 1050 is removed and the signal 1052 is received directly from the terminal 1014. In another embodiment, capacitor 1090 is located on wafer 1010. In yet another embodiment, a low pass filter and/or buffer is added to process signal 1083 before signal 1083 is received by multiplier component 1096. In yet another example, two resistors are further added to divide the processed signal 1083 before the processed signal 1083 is received by the multiplier component 1096.

In yet another example, for DCM and CRM, _{Vcs_0 is} equal to zero, so if illumination system 1000 does not need to operate in DCM and CRM for constant lamp current 1092, sample and hold component 1062 and voltage to current converter 1066 are removed. According to yet another embodiment, for CRM, clock generator 1056 is replaced by a pulse signal generator that receives Demag signal 1045 and in response generates a pulse of pulse signal 1055. In yet another example, the pulse signal 1055 is received by the flip-flop component 1054, and the different pulses of the pulse signal 1055 correspond to different switching cycles.

Figure 11 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 1100 includes a switch 5120, a diode 5130, an inductor 5140, capacitors 5150 and 5152, and a sense resistor 5160. Additionally, the illumination system 1100 further includes a comparator 1142, a demagnetization detection component 1144, a rising edge blanking component 1150, a flip-flop component 1154, a pulse signal generator 1156, and a driver component 1158. In addition, the illumination system 1100 also includes a transconductance amplifier 1186, switches 1180 and 1182, a capacitor 1190, and a ramp signal generator 1199.

For example, switch 5120, diode 5130, inductor 5140, capacitor 5150, and sense resistor 5160 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 1142, demagnetization detection component 1144, rising edge blanking component 1150, flip-flop component 1154, pulse signal generator 1156, driver component 1158, transconductance amplifier 1186, switches 1180 and 1182, and ramp signal generation The 1199 is located on the wafer 1110. In yet another example, capacitor 1190 is located outside of wafer 1110. In yet another example, wafer 1110 includes terminals 1112, 1114, 1116, 1118, and 1119.

As shown in FIG. 11, illumination system 1100 receives input voltage 1132 and provides lamp current 1192 (eg, output current) and lamp voltage to one or more LEDs 5190. In one embodiment, the current flowing through inductor 5140 is sensed by resistor 5160. For example, resistor 5160 passes through terminal 1114 and produces a current sense signal 1152 along with rising edge blanking component 1150.

In another embodiment, transconductance amplifier 1186 receives current sense signal 1152 (eg, V _cs ) and also receives predetermined voltage signal 1191 (eg, V _ref ) through switch 1180. For example, switch 1180 is controlled by signal 1185 generated based on drive signal 1159. In another example, if signal 1185 is at a logic high level, switch 1180 is closed, and if signal 1185 is at a logic low level, switch 1180 is open. In yet another example, the switch 1180 is closed during the on time of the switch 5120 and is off during the off time of the switch 5120.

In yet another embodiment, during the on-time of switch 5120, transconductance amplifier 1186 compares current sense signal 1152 (eg, V _cs ) to predetermined voltage signal 1191 (eg, V _ref ) and senses current The difference between the measured signal 1152 (eg, V _cs ) and the predetermined voltage signal 1191 (eg, V _ref ) is converted to current 1189 . For example, current 1189 is proportional to the difference between current sense signal 1152 (eg, V _cs ) and predetermined voltage signal 1191 (eg, V _ref ). In another example, during the on time of switch 5120, if the magnitude of predetermined voltage signal 1191 (eg, V _ref ) is greater than current sense signal 1152 (eg, V _cs ), current 1189 charges capacitor 1190, and If the magnitude of the predetermined voltage signal 1191 (eg, V _ref ) is less than the current sense signal 1152 (eg, V _cs ), the capacitor 1190 is discharged.

In yet another embodiment, during the off time of switch 5120, predetermined voltage signal 1191 (eg, _Vref ) is shorted to ground through switch 1182. For example, switch 1182 is controlled by signal 1145 generated based on drive signal 1159. In another example, if signal 1145 is at a logic high level, switch 1182 is closed, and if signal 1145 is at a logic low level, switch 1182 is open. In yet another example, the switch 1182 is closed during the off time of the switch 5120 and is off during the on time of the switch 5120.

As shown in FIG. 11, signal 1183 (eg, V _C ) is generated by current 1189 for charging and/or discharging capacitor 1190. In one embodiment, comparator 1142 receives signal 1183 (eg, V _C ) and also receives ramp signal 1193. For example, ramp signal 1193 (ramp) is generated by ramp signal generator 1199 in response to pulse signal 1155. In another example, in response, comparator 1142 generates a comparison signal 1143 that is received by flip-flop component 1154. In another example, the trigger assembly 1154 also receives the pulse signal 1155 from the pulse signal generator 1156 and produces a modulated signal 1157. In yet another example, the modulation signal 1157 is received by the driver component 1158, which in response outputs a drive signal 1159 to the switch 5120. In another embodiment, pulse signal generator 1156 receives Demag signal 1145 from demagnetization detection component 1144 and, in response, generates a pulse of pulse signal 1155. For example, different pulses of pulse signal 1155 correspond to different switching cycles.

As discussed above and further emphasized herein, FIG. 11 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, rising edge blanking component 1150 is removed and signal 1152 is received directly from terminal 1114. In another example, capacitor 1190 is located on wafer 1110.

Figure 12 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention. This illustration is only an example, and should not unduly limit the scope of the patent application. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. The illumination system 1200 includes a switch 5220, a diode 5230, an inductor 5240, capacitors 5250 and 5252, and a sense resistor 5260. In addition, the illumination system 1200 further includes a comparator 1242, a demagnetization detection component 1244, a rising edge blanking component 1250, a flip-flop component 1254, a pulse signal generator 1256, and a driver component 1258. In addition, the illumination system 1200 also includes a transconductance amplifier 1286, switches 1280 and 1282, a capacitor 1290, a multiplier assembly 1296, and resistors 1298 and 1299.

For example, switch 5220, diode 5230, inductor 5240, capacitor 5250, and sense resistor 5260 are identical to switch 120, diode 130, inductor 140, capacitor 150, and sense resistor 160, respectively. In another example, comparator 1242, demagnetization detection component 1244, rising edge obscuration component 1250, flip-flop component 1254, pulse signal generator 1256, driver component 1258, transconductance amplifier 1286, switches 1280 and 1282, and multiplier components 1296 is located on wafer 1210. In yet another example, capacitor 1290 is located outside of wafer 1210. In yet another example, wafer 1210 includes terminals 1212, 1214, 1216, 1217, 1218, and 1219.

As shown in FIG. 12, illumination system 1200 receives input voltage 1232 and provides rectified voltage 1293 and lamp current 1292 (eg, output current) to drive one or more LEDs 5290. In one embodiment, the current flowing through inductor 5240 is sensed by resistor 5260. For example, resistor 5260 passes through terminal 1214 and produces a current sense signal 1252 along with rising edge blanking component 1250.

In another embodiment, transconductance amplifier 1286 receives current sense signal 1252 (eg, V _cs ) and also receives a predetermined voltage signal 1291 (eg, V _ref ) through switch 1280. For example, switch 1280 is controlled by signal 1285 generated based on drive signal 1259. In another example, if signal 1285 is at a logic high level, switch 1280 is closed, and if signal 1285 is at a logic low level, switch 1280 is open. In yet another example, the switch 1280 is closed during the on time of the switch 5220 and is off during the off time of the switch 5220.

In yet another embodiment, during the on time of switch 5220, transconductance amplifier 1286 compares current sense signal 1252 (eg, V _cs ) to predetermined voltage signal 1291 (eg, V _ref ) and senses current The difference between the measured signal 1252 (eg, V _cs ) and the predetermined voltage signal 1291 (eg, V _ref ) is converted to current 1289. For example, current 1289 is proportional to the difference between current sense signal 1252 (eg, V _cs ) and predetermined voltage signal 1291 (eg, V _ref ). In another example, during the on time of switch 5220, if the magnitude of predetermined voltage signal 1291 (eg, V _ref ) is greater than current sense signal 1252 (eg, V _cs ), current 1289 charges capacitor 1290, and If the magnitude of the predetermined voltage signal 1291 (eg, V _ref ) is less than the current sense signal 1252 (eg, V _cs ), the capacitor 1290 is discharged.

In yet another embodiment, during the off time of switch 5220, predetermined voltage signal 1291 (eg, _Vref ) is shorted to ground through switch 1282. For example, switch 1282 is controlled by signal 1245 generated based on drive signal 1259. In another example, if signal 1245 is at a logic high level, switch 1282 is closed, and if signal 1245 is at a logic low level, switch 1282 is open. In yet another example, the switch 1282 is closed during the off time of the switch 5220 and is off during the on time of the switch 5220.

As shown in FIG. 12, signal 1283 (eg, V _C ) is generated by current 1289 for charging and/or discharging capacitor 1290. In one embodiment, resistor 1298 receives the rectified voltage 1293 and, together with resistor 1299, produces a signal 1295. For example, signal 1295 is received by multiplier component 1296 through terminal 1217. In another example, multiplier component 1296 also receives signal 1283 (eg, V _C ) and generates control signal 1297 based on at least information associated with signals 1295 and 1283.

In another embodiment, the comparator 1242 receives the control signal 1297 and also receives the current sense signal 1252. For example, in response, comparator 1242 generates a comparison signal 1243 that is received by flip-flop component 1254. In another example, the trigger component 1254 also receives the pulse signal 1255 from the pulse signal generator 1256 and generates a modulated signal 1257. In yet another example, the modulation signal 1257 is received by the driver component 1258, which in response outputs a drive signal 1259 to the switch 5220. In another embodiment, pulse signal generator 1256 receives Demag signal 1245 from demagnetization detection component 1244 and, in response, generates a pulse of pulse signal 1255. For example, different pulses of pulse signal 1255 correspond to different switching cycles.

As discussed above and further emphasized herein, FIG. 12 is merely an example and should not unduly limit the scope of the claimed scope. Those of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, rising edge blanking component 1250 is removed and signal 1252 is received directly from terminal 1214. In another example, capacitor 1290 is located on wafer 1210. In yet another example, a slope compensation component is added, and the comparator 1242 receives the current sense signal 1252 through the slope compensation component.

For example, some or all of the components of various embodiments of the invention, individually and/or in combination with at least one other component, utilize one or more software components, one or more hardware components, and/or one of software and hardware components or A variety of combinations to achieve. In another example, some or all of the components of various embodiments of the invention are implemented in one or more circuits, alone or in combination with at least one other component, such as in one or more analog circuits and/or one Or implemented in multiple digital circuits. In yet another example, various embodiments and/or examples of the invention may be combined. In yet another example, various embodiments and/or examples of the invention are combined such that the illumination system can be in various operating modes under certain conditions (eg, at different input voltages), such as in DCM mode, CCM mode, and A constant lamp current is provided in all modes of the CRM mode.

The invention has a wide range of applications. Certain embodiments of the present invention can be used to drive one or more light emitting diodes while achieving high power factor and precise control of constant lamp current.

In accordance with another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 3) includes: a control component (eg, component 380) configured Receiving at least a demagnetization signal (eg, signal 383), a sensing signal (eg, signal 314), and a reference signal (eg, signal 389), and generating control based on at least information associated with the demagnetization signal, the sensing signal, and the reference signal Signals (eg, signal 391); and logic and drive components (eg, components 362, 394, and 396) configured to receive at least a control signal (eg, signal 391) and based at least on a control signal (eg, signal 391) The associated information outputs a drive signal (e.g., signal 312) to a switch (e.g., component 320). A switch (eg, component 320) is coupled to a first diode terminal of a diode (eg, component 330) and a first inductor terminal of an inductor (eg, component 340). The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal. The second diode terminal and the second inductor terminal are configured to provide at least an output current to the one or more light emitting diodes. A control signal (eg, signal 391) is configured to adjust the output current to a predetermined constant current magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 3) includes receiving at least a demagnetization signal (eg, signal 383), Sensing signals (eg, signal 314) and reference signals (eg, signal 389); processing information associated with the demagnetization signal, the sensing signal, and the reference signal; and based at least on correlating with the demagnetization signal, the sensing signal, and the reference signal The information generates a control signal (eg, signal 391). Additionally, the method includes: receiving at least a control signal (eg, signal 391); processing information associated with the control signal; and directing a first diode terminal and inductor connected to the diode (eg, component 330) A switch (eg, component 320) of the first inductor terminal (eg, component 340) outputs a drive signal (eg, signal 312). The diode further includes a second diode terminal, and the inductor further includes a second inductor terminal. The second diode terminal and the second inductor terminal are configured to provide at least an output current to the one or more light emitting diodes. Moreover, the method includes adjusting the output current to a predetermined size based at least on information associated with the control signal (eg, signal 391).

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 5) includes a first signal processing component (eg, component 520), It is configured to receive at least a sensing signal (eg, signal 552) and generate a first signal (eg, signal 521). The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the system includes a second signal processing component (eg, component 522) configured to generate a second signal (eg, signal 523); an integrator component (eg, components 530 and 540) configured to receive the first And generating a third signal (eg, signal 531); and a comparator (eg, component 542) configured to process information associated with the third signal and the sensed signal and based at least on the third signal The information associated with the sensed signal produces a comparison signal (eg, signal 543). Additionally, the system includes a signal generator (eg, component 554) configured to receive at least a comparison signal and generate a modulated signal (eg, signal 557); and a gate driver (eg, component 558) configured to receive The signal is modulated (eg, signal 557) and the drive signal is output to the switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for the demagnetization process. For each of the one or more switching cycles, the first signal represents a multiplication result of the first sum value of the on-time period and the demagnetization period and the second sum value of the first current magnitude and the second current magnitude, and the second The signal indicates the switching period multiplied by the predetermined current magnitude. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal (eg, signal 531) represents the integrated cycle-by-cycle accumulated difference . The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 5) includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal Information associated with the second signal; and generating a third signal based on at least information associated with the first signal and the second signal. Moreover, the method includes: processing information associated with the third signal and the sensed signal; generating a comparison signal based on at least information associated with the third signal and the sensed signal; receiving at least the comparison signal; at least based on correlating with the comparison signal The information generates a modulated signal; receives the modulated signal; and outputs the drive signal based at least on information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-period and a demagnetization period. For each of the one or more switching cycles, the first signal represents a multiplication result of the first sum value of the on-time period and the demagnetization period and the second sum value of the first current magnitude and the second current magnitude, and the second The signal indicates the switching period multiplied by the predetermined current magnitude. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The processing for processing information associated with the first signal and the second signal includes integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal representing the integrated The difference is accumulated step by cycle. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 5) includes: a first signal processing component (eg, component 520) Configuring to receive at least a sensing signal (eg, signal 552) and generate a first signal (eg, signal 521). The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the system includes a second signal processing component (eg, component 522) configured to generate a second signal (eg, signal 523); an integrator component (eg, components 530 and 540) configured to receive the first And generating a third signal (eg, signal 531); and a comparator (eg, component 542) configured to process information associated with the third signal and the sensed signal and based at least on the third signal The information associated with the sensed signal produces a comparison signal (eg, signal 543). Additionally, the system includes a signal generator (eg, component 554) configured to receive at least a comparison signal and generate a modulated signal (eg, signal 557); and a gate driver (eg, component 558) configured to receive The signal is modulated (eg, signal 557) and the drive signal is output to the switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for the demagnetization process. For each cycle of one or more switching cycles, the first signal represents the sum of the first multiplication result and the second multiplication result, and the second signal represents the switching period multiplied by the predetermined current magnitude. The first multiplication result is equal to the sum of the first current magnitude and the second current magnitude multiplied by the on-time period. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The second multiplication result is equal to two times the demagnetization period and multiplied by the third current magnitude, and the third current magnitude represents the inductor current at the middle of the on period. The integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal (eg, signal 531) represents the integrated cycle-by-cycle accumulated difference . The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 5) includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal Information associated with the second signal; and generating a third signal based on at least information associated with the first signal and the second signal. Moreover, the method includes: processing information associated with the third signal and the sensing signal; generating a comparison signal based on at least information associated with the third signal and the sensing signal; receiving at least the comparison signal; and based at least on the comparison signal The associated information produces a modulated signal. And, the method includes: receiving a modulated signal; and outputting the drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-period and a demagnetization period. For each cycle of one or more switching cycles, the first signal represents the sum of the first multiplication result and the second multiplication result, and the second signal represents the switching period multiplied by the predetermined current magnitude. The first multiplication result is equal to the sum of the first current magnitude and the second current magnitude multiplied by the on-time period. The first current magnitude represents the inductor current at the beginning of the on-time period and the second current magnitude represents the inductor current at the end of the on-time period. The second multiplication result is equal to two times the demagnetization period and multiplied by the third current magnitude, and the third current magnitude represents the inductor current at the middle of the on period. The processing for processing information associated with the first signal and the second signal includes integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles, and the third signal representing the integrated The difference is accumulated step by cycle. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 6) includes: a first sample and hold and voltage to current conversion component (eg, components 662 and 666) are configured to receive at least a sensing signal and generate a first current signal (eg, signal 667). The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch. Additionally, the system includes: a second sample and hold and voltage to current conversion component (eg, components 664 and 668) configured to receive at least the sensed signal and generate a second current signal (eg, signal 669); and signal amplification And a voltage to current conversion component (eg, components 686 and 688) configured to receive at least the sensed signal and generate a third current signal (eg, signal 689). Additionally, the system includes: a current signal generator configured to generate a fourth current signal (eg, signal 661); and a capacitor coupled to the current signal generator, coupled to the first sample and hold by the second switch and A voltage to current conversion component and a second sample and hold and voltage to current conversion component are coupled to the signal amplification and voltage to current conversion components by a third switch. The capacitor is configured to generate a voltage signal. Moreover, the system includes a comparator (eg, component 642) configured to process information associated with a voltage signal (eg, signal 683) and a sensed signal (eg, signal 652), and based at least on the voltage signal and The information associated with the sensed signal produces a comparison signal (eg, signal 643). Additionally, the system includes: a modulated signal generator (eg, component 654) configured to receive at least a comparison signal and generate a modulated signal (eg, signal 657); and a gate driver configured to receive the modulated signal and A drive signal is output to the first switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the first switch and a demagnetization period for demagnetization processing. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For each cycle of one or more switching cycles, the first current signal and the second current signal are configured to discharge or charge the capacitor only during the demagnetization period; the third current signal is configured to only be during the on time period The capacitor is discharged or charged; and the fourth current signal is configured to charge or discharge the capacitor during the switching cycle.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 6) includes receiving at least a sensed signal. A sense signal is associated with an inductor current flowing through an inductor coupled to the switch, processing information associated with the sense signal, and generating a first current signal, a second current signal based on at least information associated with the sense signal And a third current signal. Additionally, the method includes: generating a fourth current signal; processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal; and based at least on the first current signal, the second current The information associated with the signal, the third current signal, and the fourth current signal generates a voltage signal from at least a capacitor. Moreover, the method includes: processing information associated with the voltage signal and the sensed signal; generating a comparison signal based on at least information associated with the voltage signal and the sensed signal; receiving at least the comparison signal; and based at least on the associated signal The information produces a modulated signal. Moreover, the method includes receiving a modulated signal; and outputting a drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-period and a demagnetization period. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For each cycle of one or more switching cycles, processing for processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal includes: passing only during the demagnetization period A current signal and a second current signal discharge or charge the capacitor; the capacitor is discharged or charged by the third current signal only during the on period; and the capacitor is charged or discharged by the fourth current signal during the switching period.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 7) includes: signal amplification and voltage to current conversion components (eg, Components 786 and 788) are configured to receive at least a sensed signal (eg, signal 752) and generate a first current signal (eg, signal 789). The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch. Additionally, the system includes a current signal generator configured to generate a second current signal (eg, signal 761); and a capacitor coupled to the current signal generator and coupled to the signal amplification and voltage through the second switch Current conversion component. The capacitor is configured to generate a voltage signal. Moreover, the system includes a comparator configured to process information associated with the voltage signal and the sensed signal and to generate a comparison signal based on at least information associated with the voltage signal and the sensed signal; a modulated signal generator (eg, Component 754) is configured to receive at least a comparison signal and generate a modulated signal (eg, signal 757); and a gate driver configured to receive the modulated signal and output a drive signal to the first switch. The drive signal is associated with at least one or more switching cycles, and the first current signal represents an inductor current. Each cycle of one or more switching cycles includes at least an on-time period of the first switch. For each cycle of one or more switching cycles, the first current signal is configured to discharge or charge the capacitor only during the on-time period; and the second current signal is configured to charge the capacitor only during the on-time period Or discharge.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 7) includes receiving at least a sensing signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first current signal based on at least information associated with the sensed signal; generating a second current signal; processing associated with the first current signal and the second current signal The associated information; and based on at least information associated with the first current signal and the second current signal, the voltage signal is generated by at least a capacitor. Moreover, the method includes: processing information associated with the voltage signal and the sensed signal; generating a comparison signal (eg, signal 743) based on at least information associated with the voltage signal and the sensed signal; receiving at least the comparison signal; at least based on Comparing the information associated with the signal to produce a modulated signal; receiving the modulated signal; and outputting the drive signal based at least on information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and the first current signal represents an inductor current. Each cycle of one or more switching cycles includes at least an on time period. For each cycle of one or more switching cycles, processing for processing information associated with the first current signal and the second current signal includes discharging or charging the capacitor by the first current signal only during the on-time period And charging or discharging the capacitor by the second current signal only during the on-time period.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 8 and/or FIG. 9) includes: a transconductance amplifier (eg, The component 886 and/or component 986) is configured to receive the sensing signal and also receive a predetermined voltage signal (eg, signal 891 and/or signal 991) through the first switch (eg, component 880 and/or component 980). The sense signal is associated with an inductor current flowing through an inductor coupled to a second switch (eg, component 4820 and/or component 4920), and the transconductance amplifier is further configured to generate a current signal (eg, signal 889 and / Or signal 989). Additionally, the system includes a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal (eg, signal 883 and/or signal 983); and a comparator configured to process the voltage signal and the sense signal And generating a comparison signal (eg, signal 843 and/or signal 943) based at least on information associated with the voltage signal and the sense signal. Additionally, the system includes: a modulated signal generator (eg, component 854 and/or component 954) configured to receive at least a comparison signal and generate a modulated signal (eg, signal 857 and/or signal 957); and a gate The driver is configured to receive the modulation signal and output a drive signal to the second switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the second switch. The transconductance amplifier (eg, component 886 and/or component 986) is also configured to receive at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. A current signal (eg, signal 889 and/or signal 989) is configured to charge or discharge the capacitor.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, a method as implemented in accordance with FIG. 8 and/or FIG. 9) includes receiving at least a sensing signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal (eg, signal 891 and/or signal 991); Processing information associated with the current signal. Moreover, the method includes: generating a voltage signal from at least a capacitor based on at least information associated with the current signal; processing information associated with the voltage signal and the sensing signal; and based at least on the voltage signal and the sensing signal The information produces a comparison signal. Moreover, the method includes: receiving at least a comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting the drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on time period. The process for receiving at least the sensed signal includes receiving at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. Moreover, the processing for processing information associated with the current signal includes charging or discharging the capacitor by a current signal (eg, signal 889 and/or signal 989).

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 10) includes: a first sample and hold and voltage to current conversion component (eg, components 1062 and 1066) are configured to receive at least a sensing signal and generate a first current signal (eg, signal 1067). The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch. Additionally, the system includes: a second sample and hold and voltage to current conversion component (eg, components 1064 and 1068) configured to receive at least the sensed signal and generate a second current signal (eg, signal 1069); signal amplification and A voltage to current conversion component (eg, components 1086 and 1088) is configured to receive at least a sensing signal and generate a third current signal (eg, signal 1089); a current signal generator configured to generate a fourth current signal (eg, a signal 1061); and a capacitor coupled to the current signal generator, coupled to the first sample and hold and voltage to current conversion components and the second sample and hold and voltage to current conversion components through the second switch, and through The three switches are coupled to a signal amplification and voltage to current conversion component, the capacitor being configured to generate a first voltage signal (eg, signal 1083). Moreover, the system includes a multiplier component (eg, component 1096) configured to process information associated with a first voltage signal (eg, signal 1083) and a second voltage signal (eg, signal 1093), and based at least on The information associated with the first voltage signal and the second voltage signal produces a multiplicative signal. Moreover, the system includes a comparator (eg, component 1042) configured to receive the multiply and sense signals and to generate a comparison signal (eg, signal 1043) based on at least information associated with the multiply and sense signals; A modulation signal generator (eg, component 1054) configured to receive at least a comparison signal and generate a modulation signal (eg, signal 1057); and a gate driver configured to receive the modulation signal and output the drive to the first switch signal. The drive signal is associated with at least a plurality of switching cycles, and each of the plurality of switching cycles includes at least an on-period of the first switch and a demagnetization period for the demagnetization process. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For a plurality of switching cycles, the first current signal and the second current signal are configured to discharge or charge the capacitor only during the demagnetization period; the third current signal is configured to discharge or charge the capacitor only during the on-time period; The fourth current signal is configured to charge or discharge the capacitor during the switching cycle.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 10) includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes processing information associated with the sensed signal; and generating the first current signal, the second current signal, and the third current signal based on at least information associated with the sensed signal. Additionally, the method includes: generating a fourth current signal; processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal; and based at least on the first current signal, the second current The information associated with the signal, the third current signal, and the fourth current signal generates a first voltage signal from at least a capacitor. Moreover, the method includes: processing information associated with the first voltage signal and the second voltage signal; generating a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal; receiving the multiplication signal and the sensing signal; And generating a comparison signal based on at least information associated with the multiplication signal and the sensed signal. Additionally, the method includes: receiving at least a comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting the drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least a plurality of switching cycles, and each of the plurality of switching cycles includes at least an on-period and a demagnetization period. The first current signal represents the inductor current at the beginning of the on-time period; the second current signal represents the inductor current at the end of the on-time period; and the third current signal represents the inductor current. For each of the plurality of switching cycles, processing for processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal includes: passing the first current only during the demagnetization period The signal and the second current signal discharge or charge the capacitor; the capacitor is discharged or charged by the third current signal only during the on-time period; and the capacitor is charged or discharged by the fourth current signal during the switching period.

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 11) includes: a transconductance amplifier (eg, component 1186), The configuration is configured to receive a sensing signal and also receive a predetermined voltage signal (eg, signal 1191) through a first switch (eg, component 1180). The sense signal is associated with an inductor current flowing through an inductor coupled to a second switch (eg, component 5120), which is also configured to generate a current signal (eg, signal 1189). Additionally, the system includes a capacitor (eg, component 1190) coupled to the transconductance amplifier and configured to generate a voltage signal (eg, signal 1183); and a comparator configured to process the voltage signal (eg, signal 1183) And information associated with the ramp signal (eg, signal 1193) and generating a comparison signal (eg, signal 1143) based at least on information associated with the voltage signal and the ramp signal. Additionally, the system includes a modulated signal generator (eg, component 1154) configured to receive at least a comparison signal and generate a modulated signal (eg, signal 1157); and a gate driver configured to receive the modulated signal and A drive signal is output to the second switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the second switch. The transconductance amplifier (eg, component 1186) is also configured to receive at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. A current signal (eg, signal 1189) is configured to charge or discharge the capacitor.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 11) includes receiving at least a sensing signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes processing information associated with the sensed signal and a predetermined voltage signal (eg, signal 1191); generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing associated with the current signal And at least based on the information associated with the current signal, the voltage signal is generated by at least a capacitor. Moreover, the method includes processing information associated with the voltage signal and the ramp signal; generating a comparison signal (eg, signal 1143) based on at least information associated with the voltage signal and the ramp signal (eg, signal 1193); receiving at least the comparison signal And generating a modulated signal based at least on information associated with the comparison signal. Moreover, the method includes receiving a modulated signal; and outputting a drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on time period. The process for receiving at least the sensed signal includes receiving at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles; and processing for processing information associated with the current signal includes The capacitor is charged or discharged by a current signal (eg, signal 1189).

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 12) includes: a transconductance amplifier (eg, component 1286), The configuration is configured to receive a sensing signal and also receive a predetermined voltage signal (eg, signal 1291) through a first switch (eg, component 1280). The sense signal is associated with an inductor current flowing through an inductor coupled to the second switch, and the transconductance amplifier (eg, component 1286) is also configured to generate a current signal (eg, signal 1289). Additionally, the system includes a capacitor coupled to the transconductance amplifier and configured to generate a first voltage signal (eg, signal 1283); and a multiplier component (eg, component 1296) configured to process the first voltage signal And information associated with the second voltage signal, and generating a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal. Moreover, the system includes a comparator (eg, component 1242) configured to receive the multiplication signal and the sense signal and to generate a comparison signal based on at least information associated with the multiply signal and the sense signal; a modulated signal generator (eg, And a component 1254) configured to receive at least the comparison signal and generate a modulated signal (eg, signal 1257); and a gate driver configured to receive the modulated signal and output the drive signal to the second switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the second switch. The transconductance amplifier (eg, component 1286) is also configured to receive at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles. A current signal (eg, signal 1289) is configured to charge or discharge the capacitor.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 12) includes receiving at least a sensing signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal (eg, signal 1291); processing associated with the current signal And generating a first voltage signal (eg, signal 1283) by at least a capacitor based on at least information associated with the current signal. Moreover, the method includes processing information associated with the first voltage signal and the second voltage signal (eg, signal 1293); generating a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal; receiving multiplication And a sense signal; and generating a comparison signal based on at least information associated with the multiply signal and the sensed signal. Moreover, the method includes: receiving at least a comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting the drive signal based on at least information associated with the modulation signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on time period. The process for receiving at least the sensed signal includes receiving at least a predetermined voltage signal during the on-time period for each cycle of the one or more switching cycles; and processing for processing information associated with the current signal includes The capacitor is charged or discharged by a current signal (eg, signal 1289).

In accordance with yet another embodiment, a system for providing at least an output current to one or more light emitting diodes (eg, a system as implemented in accordance with FIG. 5) includes a first signal processing component configured to receive at least The signal is sensed and a first signal is generated. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the system includes: a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and to generate a third signal; a comparator configured to process The three signals are associated with the sensed signal and the comparison signal is generated based at least on information associated with the third signal and the sensed signal. Additionally, the system includes a signal generator configured to receive at least the comparison signal and generate a modulation signal, and a gate driver configured to receive the modulation signal and output the drive signal to the switch. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for the demagnetization process. The first signal processing component is further configured to sample the sensed signal in the middle of the on-time period for each of the one or more switching cycles; to maintain the sampled current indicative of the inductor current at the middle of the on-time period a sensed signal; and generating a first signal indicative of a sum of the first multiplication result and the second multiplication result based at least on information associated with the sampled and held sensed signal. For each cycle of one or more switching cycles, the second signal represents the switching period multiplied by a predetermined current magnitude. The integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles; and the third signal represents the integrated cycle-by-cycle accumulated difference. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

In accordance with yet another embodiment, a method for providing at least an output current to one or more light emitting diodes (eg, as implemented in accordance with FIG. 5) includes receiving at least a sensed signal. The sense signal is associated with an inductor current flowing through an inductor coupled to the switch. Additionally, the method includes: processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal Information associated with the second signal; and generating a third signal based on at least information associated with the first signal and the second signal. Moreover, the method includes: processing information associated with the third signal and the sensing signal; generating a comparison signal based on at least information associated with the third signal and the sensing signal; receiving at least the comparison signal; and based at least on the comparison signal The associated information produces a modulated signal. Moreover, the method includes receiving a modulated signal; and outputting a drive signal based on at least information associated with the modulated signal. The drive signal is associated with at least one or more switching cycles, and each of the one or more switching cycles includes at least an on-time period of the switch and a demagnetization period for demagnetization processing; for processing associated with the sensed signal The processing of the information includes: sampling the sensing signal in the middle of the on-time period for each of the one or more switching cycles; and maintaining the sensing of the inductor current sampled in the middle of the on-time period signal. For each of the one or more switching cycles, a first signal generated based on at least information associated with the sensed signal that is sampled and held represents a sum of the first multiplication result and the second multiplication result; and the second signal representation The switching period is multiplied by the predetermined current magnitude. Processing for processing information associated with the first signal and the second signal includes integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles; and the third signal representing the integration The cycle-by-cycle cumulative difference. The post-period cumulative difference after integration is less than a predetermined threshold in magnitude.

Although specific embodiments of the invention have been described, it will be understood by those of ordinary skill in the art that <RTIgt; Therefore, it is to be understood that the invention is not limited by

100. . . Lighting system

110. . . Pulse Width Modulation (PWM) Controller

112. . . Drive signal

114. . . Current sensing signal

120. . . switch

122, 124, 126. . . Terminal

130. . . Dipole

140. . . Inductor

150, 152. . . Capacitor

160. . . Sense resistor

190. . . led

192. . . Lamp current

210, 220, 230. . . Waveform

300. . . Lighting system

308. . . Rising edge masking component

310. . . Pulse Width Modulation (PWM) Controller

312. . . Drive signal

314. . . Current sensing signal

320. . . switch

330. . . Dipole

332. . . Input voltage

340. . . Inductor

350, 352. . . Capacitor

354. . . signal

360. . . Sense resistor

362. . . Logical component

364. . . Capacitor

372, 374, 376, 378, 379. . . Terminal

380. . . Constant current control component

381. . . Reference voltage signal

382. . . Demagnetization component

383. . . Demagnetization signal

384. . . Overcurrent protection (OCP) components

385. . . control signal

386. . . Clock generator

387. . . Clock signal

388. . . Reference signal generator

389. . . Reference current signal

390. . . led

391. . . control signal

392. . . Lamp current

393. . . Logic signal

394. . . Trigger component

395. . . Modulated signal

396. . . Drive component

420. . . switch

430. . . Dipole

440. . . Inductor

450, 452. . . Capacitor

460. . . Sense resistor

500. . . Lighting system

510. . . Wafer

512, 514, 516, 518, 519. . . Terminal

520, 522. . . Processing components on a cycle-by-cycle basis

521, 523. . . signal

530. . . Capacitor

531. . . Integrator produces signal

532. . . Input voltage

533. . . Signal conditioning component

540. . . Transconductance amplifier

542. . . Comparators

543. . . Comparison signal

544. . . Demagnetization detection component

545. . . Demag signal

550. . . Rising edge masking component

551. . . Feedback signal

552. . . Current sensing signal

554. . . Trigger component

555. . . Clock signal

556. . . Clock generator

557. . . Modulated signal

558. . . Drive component

559. . . Drive signal

590. . . led

592. . . Lamp current

600. . . Lighting system

610. . . Wafer

612, 614, 616, 618, 619. . . Terminal

632. . . Input voltage

642. . . Comparators

643. . . Comparison signal

644. . . Demagnetization detection component

645. . . Demag signal

650. . . Rising edge masking component

652. . . Current sensing signal

654. . . Trigger component

655. . . Clock signal

656. . . Clock generator

657. . . Modulated signal

658. . . Drive component

659. . . Drive signal

660, 666, 668, 688. . . Voltage to current converter

661. . . Charging current / control signal

662, 664. . . Sample and hold component

663,665. . . Voltage signal

667. . . Current signal

669. . . Current signal

680. . . switch

681. . . Discharge current

682. . . switch

683. . . signal

684. . . Slope compensation component

685. . . signal

686. . . signal amplifier

687. . . Voltage signal

689. . . Discharge current

690. . . Capacitor

691. . . Predetermined voltage signal

692. . . Lamp current

700. . . Lighting system

710. . . Wafer

712, 714, 718, 719. . . Terminal

732. . . Input voltage

742. . . Comparators

743. . . Comparison signal

750. . . Rising edge masking component

752. . . Current sensing signal

754. . . Trigger component

755. . . Clock signal

756. . . Clock generator

757. . . Modulated signal

758. . . Drive component

759. . . Drive signal

760. . . Voltage to current converter

761. . . recharging current

780, 782. . . switch

783. . . signal

784. . . Slope compensation component

785. . . signal

786. . . signal amplifier

787. . . Voltage signal

788. . . Voltage to current converter

789. . . Discharge current

790. . . Capacitor

791. . . Predetermined voltage signal

792. . . Lamp current

800. . . Lighting system

810. . . Wafer

812, 814, 818, 819. . . Terminal

832. . . Input voltage

842. . . Comparators

843. . . Comparison signal

845. . . signal

850. . . Rising edge masking component

852. . . Current sensing signal

854. . . Trigger component

855. . . Clock signal

856. . . Clock generator

857. . . Modulated signal

858. . . Drive component

859. . . Drive signal

880, 882. . . switch

883. . . signal

884. . . Slope compensation component

885. . . signal

886. . . Transconductance amplifier

889. . . Current

890. . . Capacitor

891. . . Predetermined voltage signal

892. . . Lamp current

900. . . Lighting system

910. . . Wafer

912, 914, 916, 918, 919. . . Terminal

932. . . Input voltage

942. . . Comparators

943. . . Comparison signal

944. . . Demagnetization detection component

945. . . signal

950. . . Rising edge masking component

952. . . Current sensing signal

954. . . Trigger component

955. . . Pulse signal

956. . . Pulse signal generator

957. . . Modulated signal

958. . . Drive component

959. . . Drive signal

980, 982. . . switch

983, 985. . . signal

986. . . Transconductance amplifier

989. . . Current

990. . . Capacitor

991. . . Predetermined voltage signal

992. . . Lamp current

1000. . . Lighting system

1010. . . Wafer

1012, 1014, 1016, 1017, 1018, 1019. . . Terminal

1032. . . Input voltage

1042. . . Comparators

1043. . . Comparison signal

1044. . . Demagnetization detection component

1045. . . Demag signal

1050. . . Rising edge masking component

1052. . . Current sensing signal

1054. . . Trigger component

1055. . . Clock signal

1056. . . Clock generator

1057. . . Modulated signal

1058. . . Actuator assembly

1059. . . Drive signal

1060, 1066, 1068, 1088. . . Voltage to current converter

1061. . . Charging current / control signal

1062, 1064. . . Sample and hold component

1063, 1065. . . Voltage signal

1067, 1069. . . Current signal

1080. . . switch

1081. . . Discharge current

1082. . . switch

1083. . . signal

1084. . . Slope compensation component

1085. . . signal

1086. . . Transconductance amplifier

1087. . . Voltage signal

1089. . . Discharge current

1090. . . Capacitor

1091. . . Predetermined voltage signal

1092. . . Lamp current

1093. . . Rectified voltage

1095. . . signal

1096. . . Multiplier component

1097. . . control signal

1098, 1099. . . Resistor

1100. . . Lighting system

1110. . . Wafer

1112, 1114, 1116, 1118, 1119. . . Terminal

1132. . . Input voltage

1142. . . Comparators

1143. . . Comparison signal

1144. . . Demagnetization detection component

1145. . . signal

1150. . . Rising edge masking component

1152. . . Current sensing signal

1154. . . Trigger component

1155. . . Pulse signal

1156. . . Pulse signal generator

1157. . . Modulated signal

1158. . . Drive component

1159. . . Drive signal

1180, 1182. . . switch

1183, 1185. . . signal

1186. . . Transconductance amplifier

1189. . . Current

1190. . . Capacitor

1191. . . Predetermined voltage signal

1192. . . Lamp current

1193. . . Ramp signal

1199. . . Ramp signal generator

1200. . . Lighting system

1210. . . Wafer

1212, 1214, 1216, 1217, 1218, 1219. . . Terminal

1232. . . Input voltage

1242. . . Comparators

1243. . . Comparison signal

1244. . . Demagnetization detection component

1245. . . Demag signal

1250. . . Rising edge masking component

1252. . . Current sensing signal

1254. . . Trigger component

1255. . . Pulse signal

1256. . . Pulse signal generator

1257. . . Modulated signal

1258. . . Drive component

1259. . . Drive signal

1280, 1282. . . switch

1283, 1285. . . signal

1286. . . Transconductance amplifier

1289. . . Current

1290. . . Capacitor

1291. . . Predetermined voltage signal

1292. . . Lamp current

1293. . . Rectified voltage

1295. . . signal

1296. . . Multiplier component

1297. . . control signal

1298. . . Resistor

1299. . . Resistor

4620. . . switch

4630. . . Dipole

4640. . . Inductor

4650, 4652. . . Capacitor

4660. . . Sense resistor

4690. . . led

4720. . . switch

4730. . . Dipole

4740. . . Inductor

4750. . . Capacitor

4760. . . Sense resistor

4790. . . led

4820. . . switch

4830. . . Dipole

4840. . . Inductor

4850. . . Capacitor

4860. . . Sense resistor

4890. . . led

4920. . . switch

4930. . . Dipole

4940. . . Inductor

4950, 4952. . . Capacitor

4960. . . Sense resistor

4990. . . led

5020. . . switch

5030. . . Dipole

5040. . . Inductor

5050, 5052. . . Capacitor

5060. . . Sense resistor

5090. . . led

5120. . . switch

5130. . . Dipole

5140. . . Inductor

5150, 5152. . . Capacitor

5160. . . Sense resistor

5190. . . led

5220. . . switch

5230. . . Dipole

5240. . . Inductor

5250, 5252. . . Capacitor

5260. . . Sense resistor

5290. . . led

Figure 1 is a simplified diagram showing a conventional LED lighting system with a Buck converter;

Figure 2 is a simplified diagram showing the operational mechanism of a lighting system operating in discontinuous conduction mode (DCM);

Figure 3 is a simplified diagram showing an LED illumination system in accordance with one embodiment of the present invention;

4A, 4B, and 4C are simplified diagrams showing timing diagrams of illumination system 300 operating in discontinuous conduction mode (DCM), continuous conduction mode (CCM), and critical conduction mode (CRM), respectively. ;

Figure 5 is a simplified diagram of an LED illumination system in accordance with another embodiment of the present invention;

Figure 6 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention;

Figure 7 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention;

Figure 8 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention;

Figure 9 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention;

Figure 10 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention;

Figure 11 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention;

Figure 12 is a simplified diagram of an LED illumination system in accordance with yet another embodiment of the present invention.

300. . . Lighting system

308. . . Rising edge masking component

310. . . Pulse Width Modulation (PWM) Controller

312. . . Drive signal

314. . . Current sensing signal

320. . . switch

330. . . Dipole

332. . . Input voltage

340. . . Inductor

350, 352. . . Capacitor

354. . . signal

360. . . Sense resistor

362. . . Logical component

364. . . Capacitor

372, 374, 376, 378, 379. . . Terminal

380. . . Constant current control component

381. . . Reference voltage signal

382. . . Demagnetization component

383. . . Demagnetization signal

384. . . Overcurrent protection (OCP) components

385. . . control signal

386. . . Clock generator

387. . . Clock signal

388. . . Reference signal generator

389. . . Reference current signal

390. . . led

391. . . control signal

392. . . Lamp current

393. . . Logic signal

394. . . Trigger component

395. . . Modulated signal

396. . . Drive component

Claims (73)

A system for providing at least an output current to one or more light emitting diodes, the system comprising: a control component configured to receive at least a demagnetization signal, a sensing signal, and a reference signal, and based at least on the demagnetization signal, The sensing signal and the information associated with the reference signal generate a control signal; and a logic and drive component configured to receive the control signal and output a drive signal to the switch based on at least information associated with the control signal; The switch is connected to the first diode terminal of the diode and the first inductor terminal of the inductor, the diode further includes a second diode terminal, the inductor further comprising a second inductor terminal; The diode terminal and the second inductor terminal are configured to provide at least the output current to the one or more light emitting diodes; the control signal is configured to adjust the output current to a predetermined constant current magnitude. A system for providing at least an output current to one or more light emitting diodes as recited in claim 1, further comprising a demagnetization component configured to receive the first diode directly or indirectly And a feedback signal of the terminal and the first inductor terminal, and generating the demagnetization signal based at least on information associated with the feedback signal. A system for providing at least an output current to one or more light emitting diodes as described in claim 2, wherein the demagnetization component is further configured to receive the first diode terminal from at least via a capacitor And the feedback signal of the first inductor terminal. A system for providing at least an output current to one or more light emitting diodes as described in claim 2, wherein the demagnetization signal comprises one or more associated with one or more pulse widths, respectively. A pulse, each of the one or more pulse widths corresponding to a demagnetization period. A system for providing at least an output current to one or more light emitting diodes as recited in claim 1, wherein the sensing signal flows through if the switch is closed in response to the driving signal The current of the switch is associated. A system for providing at least an output current to one or more light emitting diodes as described in claim 1 wherein the reference signal is a reference current associated with a constant current magnitude. A system for providing at least an output current to one or more light emitting diodes, as described in claim 1, wherein the control component is further configured to receive at least the drive signal and based at least on the demagnetization signal The sensing signal, the reference signal, and the information associated with the driving signal generate the control signal. A system for providing at least an output current to one or more light emitting diodes, as described in claim 7, wherein the control component is further configured to receive at least a clock signal and based at least on the demagnetization signal, The sense signal, the reference signal, the drive signal, and information associated with the clock signal generate the control signal. A system for providing at least an output current to one or more light emitting diodes, as described in claim 7, wherein the logic and drive component is further configured to receive at least the clock signal and based at least on The control signal and the information associated with the clock signal output the drive signal to the switch, the clock signal corresponding to a switching frequency of the drive signal. A system for providing at least an output current to one or more light emitting diodes as recited in claim 1, wherein the logic and drive component comprises: a logic component configured to receive the control signal; triggering And a drive component coupled to at least the trigger component and configured to generate the drive signal. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a demagnetization signal, a sensing signal, and a reference signal; processing and demagnetizing the signal, the sensing signal, and the reference signal Associated information; generating a control signal based at least on information associated with the demagnetization signal, the sensing signal, and the reference signal; receiving at least the control signal; processing information associated with the control signal; connecting to the pole a switching output driving signal of the first diode terminal of the body and the first inductor terminal of the inductor, the diode further comprising a second diode terminal, the inductor further comprising a second inductor terminal, the second a diode terminal and the second inductor terminal are configured to provide at least the output current to the one or more light emitting diodes; and adjust the output current to a predetermined value based on at least information associated with the control signal Constant current size. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a first signal processing component configured to receive at least a sensing signal and generate a first signal, the sensing signal and the stream An inductor current coupled to an inductor coupled to the switch; a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and generate a third signal a comparator configured to process information associated with the third signal and the sensed signal and to generate a comparison signal based on at least information associated with the third signal and the sensed signal; a signal generator configured to Receiving at least the comparison signal and generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the switch; wherein the drive signal is associated with at least one or more switching cycles, the one Or each period of the plurality of switching cycles includes at least an on-period of the switch and a demagnetization period for demagnetization processing; wherein, Each of the one or more switching cycles, the first signal representing a multiplication result of the first sum value of the on-period and the demagnetization period and a second sum of the first current magnitude and the second current magnitude, The first current magnitude represents the inductor current at the beginning of the on-time period, the second current magnitude representing the inductor current at the end of the on-time period; and the second signal represents the switching period multiplied by a predetermined reference current magnitude; wherein: the integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles; and the third signal represents the integrated The difference is added cycle by cycle, and the integrated cycle-by-cycle accumulated difference is smaller than a predetermined threshold in magnitude. A system for providing at least an output current to one or more light emitting diodes as described in claim 12, wherein: the integrator component comprises a transconductance amplifier and a capacitor; the transconductance amplifier is configured to receive The first signal and the second signal; and the capacitor is coupled to the transconductance amplifier and the comparator, either directly or indirectly. A system for providing at least an output current to one or more light emitting diodes as described in claim 12, configured to output the current in a discontinuous conduction mode, a continuous conduction mode, and a critical conduction mode Adjust to a predetermined constant current size. A system for providing at least an output current to one or more light emitting diodes as described in claim 12, configured to adjust the output current to a predetermined constant current magnitude in a discontinuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 12, configured to adjust the output current to a predetermined constant current magnitude in a continuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 12, configured to adjust the output current to a predetermined constant current magnitude in a critical conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal and Information associated with the second signal; generating a third signal based on at least information associated with the first signal and the second signal; processing information associated with the third signal and the sensed signal; based at least on The third signal and the information associated with the sensing signal generate a comparison signal; receiving at least the comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and based at least on the modulation The signal associated information outputs a drive signal; wherein the drive signal is associated with at least one or more switching cycles, each week of the one or more switching cycles At least an on-time period and a demagnetization period; wherein, for each of the one or more switching periods, the first signal represents a first sum value of the on-time period and the demagnetization period and a first current magnitude and a result of multiplication of a second sum value of the second current magnitude, the first current magnitude representing the inductor current at the beginning of the turn-on period, the second current magnitude representing the inductor at the end of the turn-on period And the second signal is indicative of the switching period multiplied by a predetermined reference current magnitude; wherein: processing for processing information associated with the first signal and the second signal comprises for a plurality of switching cycles, the A cycle-by-cycle difference between a signal and the second signal is integrated; and the third signal represents an integrated cycle-by-cycle accumulated difference, the integrated cycle-by-cycle accumulated difference being less than a predetermined threshold in magnitude. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a first signal processing component configured to receive at least a sensing signal and generate a first signal, the sensing signal and the stream An inductor current coupled to an inductor coupled to the switch; a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and generate a third signal a comparator configured to process information associated with the third signal and the sensed signal and to generate a comparison signal based on at least information associated with the third signal and the sensed signal; a signal generator configured to Receiving at least the comparison signal and generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the switch; wherein the drive signal is associated with at least one or more switching cycles, the one Or each period of the plurality of switching cycles includes at least an on-period of the switch and a demagnetization period for demagnetization processing; wherein, For each period of one or more switching cycles, the first signal represents a sum of the first multiplication result and the second multiplication result, the first multiplication result being equal to a sum of the first current magnitude and the second current magnitude multiplied by An on-time period, the first current magnitude representing the inductor current at the beginning of the on-time period, the second current magnitude representing the inductor current at the end of the on-time period, the second multiplication result Equal to two times the demagnetization period and multiplied by a third current magnitude, the third current magnitude representing the inductor current in the middle of the on-time period; and the second signal representing the switching period multiplied by a predetermined reference a current magnitude; wherein: the integrator component is further configured to integrate a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles; and the third signal represents a cycle-by-cycle after integration The difference is accumulated, and the integrated cycle-by-cycle accumulated difference is smaller than a predetermined threshold in magnitude. A system for providing at least an output current to one or more light emitting diodes as recited in claim 19, wherein the demagnetization period represents discontinuity for each period of the one or more switching cycles The duration of the demagnetization process in the conduction mode and the critical conduction mode. The system of claim 19, wherein for each cycle of the one or more switching cycles, the demagnetization period is equal to the off period of the switch in the continuous conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal and Information associated with the second signal; generating a third signal based on at least information associated with the first signal and the second signal; processing information associated with the third signal and the sensed signal; based at least on The third signal and the information associated with the sensing signal generate a comparison signal; receiving at least the comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and based at least on the modulation The signal associated information outputs a drive signal; wherein the drive signal is associated with at least one or more switching cycles, each week of the one or more switching cycles At least an on-time period and a demagnetization period; wherein, for each of the one or more switching periods, the first signal represents a sum of a first multiplication result and a second multiplication result, the first multiplication result being equal to the The sum of the first current magnitude and the second current magnitude is multiplied by an on-time period, the first current magnitude representing the inductor current at the beginning of the on-time period, the second current magnitude being indicative of the on-time The inductor current at the end of the segment, the second multiplication result being equal to two times the demagnetization period and multiplied by a third current magnitude, the third current magnitude representing the inductor current in the middle of the on-time period And the second signal represents the switching period multiplied by a predetermined current magnitude; wherein: processing for processing information associated with the first signal and the second signal comprises, for a plurality of switching cycles, the first signal Integrating the cycle-by-cycle difference between the second signals; and the third signal represents the integrated cycle-by-cycle accumulated difference, the integrated cycle-by-cycle accumulated difference being smaller than the pre- Threshold. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a first sample and hold and voltage to current conversion component configured to receive at least a sensed signal and generate a first current signal The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch; a second sample and hold and voltage to current conversion component configured to receive at least the sense signal and generate a second current signal a signal amplification and voltage to current conversion component configured to receive at least the sensing signal and generate a third current signal; a current signal generator configured to generate a fourth current signal; a capacitor coupled to the current signal generator Connected to the first sample and hold and voltage to current conversion components and the second sample and hold and voltage to current conversion components by a second switch, and coupled to the signal amplification and voltage to current conversion by a third switch a component configured to generate a voltage signal; a comparator configured to process the electrical Generating a signal associated with the sensed signal and generating a comparison signal based at least on information associated with the voltage signal and the sensed signal; a modulated signal generator configured to receive at least the comparison signal and generate a modulated signal And a gate driver configured to receive the modulation signal and output a drive signal to the first switch; wherein: the drive signal is associated with at least one or more switching cycles, each of the one or more switching cycles The cycle includes at least an on-period of the first switch and a demagnetization period for demagnetization processing; the first current signal represents an inductor current at the beginning of the on-time period; the second current signal is indicative of the on-time An inductor current at the end of the time period; the third current signal representing the inductor current; wherein, for each cycle of the one or more switching cycles, the first current signal and the second current signal are configured to only Discharging or charging the capacitor during the demagnetization period; the third current signal is configured to place the capacitor only during the on period Or charging; and the fourth current signal is configured to charge or discharge the capacitor during the switching period. A system for providing at least an output current to one or more light emitting diodes as recited in claim 23, wherein the switching cycle is multiplied by the cycle for each of the one or more switching cycles The fourth current signal is equal to the first quantity and the second quantity of the first sum value, the first quantity being equal to the third current signal at the end of the on-time period multiplied by half of the on-time period, the second quantity A second sum value equal to the magnitude of the first current signal and the second current signal is multiplied by the demagnetization period. A system for providing at least an output current to one or more light emitting diodes according to claim 23, wherein the signal amplification and voltage to current conversion component comprises a signal amplifying component and a voltage to current converting component . A system for providing at least an output current to one or more light emitting diodes as described in claim 23, wherein: the first sample and hold and voltage to current conversion components, the second sample and hold And a voltage to current conversion component, the signal amplification and voltage to current conversion component, the current signal generator, the comparator, the modulation signal generator, and the gate driver are located on a wafer; and the capacitor is located outside the wafer . A system for providing at least an output current to one or more light emitting diodes as described in claim 23, configured to output the current in a discontinuous conduction mode, a continuous conduction mode, and a critical conduction mode Adjust to a predetermined constant current size. A system for providing at least an output current to one or more light emitting diodes as described in claim 23, configured to adjust the output current to a predetermined constant current magnitude in a discontinuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 23, configured to adjust the output current to a predetermined constant current magnitude in a continuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 23, configured to adjust the output current to a predetermined constant current magnitude in a critical conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal; generating a first current signal, a second current signal, and a third current signal based on at least information associated with the sensed signal; generating a fourth current signal; processing and the first current Information associated with the signal, the second current signal, the third current signal, and the fourth current signal; based at least on the first current signal, the second current signal, the third current signal, and the fourth current signal Associated information, generating a voltage signal from at least a capacitor; processing information associated with the voltage signal and the sensed signal; generating a comparison signal based on at least information associated with the voltage signal and the sensed signal; receiving at least the Comparing a signal; generating a modulated signal based on at least information associated with the comparison signal; receiving the modulated signal; and based at least on the modulation An associated information output drive signal; wherein: the drive signal is associated with at least one or more switching cycles, each of the one or more switching cycles including at least an on-period and a demagnetization period; the first current The signal represents an inductor current at the beginning of the on-time period; the second current signal represents an inductor current at the end of the on-time period; the third current signal represents the inductor current; wherein, for the one Or processing for processing information associated with the first current signal, the second current signal, the third current signal, and the fourth current signal, each cycle of the plurality of switching cycles, including: only during the demagnetization period Discharging or charging the capacitor by the first current signal and the second current signal; discharging or charging the capacitor by the third current signal only during the on-time period; and passing the first period during the switching period The four current signals charge or discharge the capacitor. A method for providing at least an output current to one or more light emitting diodes as described in claim 31, wherein the switching period is multiplied by the period for each of the one or more switching cycles The fourth current signal is equal to the first sum of the first quantity and the second quantity, the first quantity being equal to the third current signal at the end of the on-time period multiplied by half of the on-time period, the second quantity being equal to The second sum value of the magnitude of the first current signal and the second current signal is multiplied by the demagnetization period. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a signal amplification and voltage to current conversion component configured to receive at least a sensing signal and generate a first current signal, the sense The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch; a current signal generator configured to generate a second current signal; a capacitor coupled to the current signal generator and passing through the second switch Coupled to the signal amplification and voltage to current conversion component, the capacitor configured to generate a voltage signal; a comparator configured to process information associated with the voltage signal and the sense signal and based at least on the voltage signal and The information associated with the sense signal produces a comparison signal; the modulation signal generator configured to receive at least the comparison signal and generate a modulation signal; and a gate driver configured to receive the modulation signal and to the first a switch output drive signal; wherein: the drive signal is associated with at least one or more switching cycles, the one Each cycle of the plurality of switching cycles includes at least an on-period of the first switch; and the first current signal represents the inductor current; wherein, for each cycle of the one or more switching cycles, the A current signal is configured to discharge or charge the capacitor only during the on-time period; and the second current signal is configured to charge or discharge the capacitor only during the on-time period. A system for providing at least an output current to one or more light emitting diodes according to claim 33, wherein the signal amplification and voltage to current conversion component comprises a signal amplifying component and a voltage to current converting component . A system for supplying at least an output current to one or more light emitting diodes as described in claim 33, wherein: the signal amplification and voltage to current conversion component, the current signal generator, the comparator The modulation signal generator and the gate driver are located on the wafer; and the capacitor is located outside the wafer. A system for providing at least an output current to one or more light emitting diodes as described in claim 33, configured to adjust the output current to a predetermined constant current magnitude in a continuous conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal; generating a first current signal based on at least information associated with the sensed signal; generating a second current signal; processing associated with the first current signal and the second current signal Information; generating a voltage signal from at least a capacitor based on at least information associated with the first current signal and the second current signal; processing information associated with the voltage signal and the sensing signal; based at least on the voltage signal And the information associated with the sensed signal produces a comparison signal; receiving at least the comparison signal; generating a modulated signal based on at least information associated with the comparison signal; receiving the modulated signal; and based at least on correlating with the modulated signal Information output drive signal; wherein: the drive signal is associated with at least one or more switching cycles, the one or more Each cycle of the cycle includes at least an on-time period; and the first current signal represents the inductor current; wherein, for each of the one or more switching cycles, for processing the first current signal and the The processing of the information associated with the second current signal includes discharging or charging the capacitor by the first current signal only during the on-time period; and passing the second current signal only during the on-time period The capacitor is charged or discharged. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a transconductance amplifier configured to receive a sensing signal and also receive a predetermined voltage signal through a first switch, the sensing signal Associated with an inductor current flowing through an inductor coupled to a second switch, the transconductance amplifier is further configured to generate a current signal; a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal; a comparator, Configuring to process information associated with the voltage signal and the sensed signal and generating a comparison signal based at least on information associated with the voltage signal and the sensed signal; a modulated signal generator configured to receive at least the comparison And generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the second switch; wherein: the drive signal is associated with at least one or more switching cycles, the one or more Each cycle of the switching cycle includes at least an on-time period of the second switch; the transconductance amplifier is further configured to Each period of one or more switching periods, only the signals received at least a predetermined voltage during the on period; and the current signal is configured to charge or discharge the capacitor. A system for providing at least an output current to one or more light emitting diodes according to claim 38, wherein: the transconductance amplifier, the comparator, the modulation signal generator, and the gate The driver is on the wafer; and the capacitor is located outside the wafer. A system for providing at least an output current to one or more light emitting diodes as described in claim 38, configured to adjust the output current to a predetermined constant in a continuous conduction mode and a critical conduction mode. Current size. A system for providing at least an output current to one or more light emitting diodes as described in claim 38 of the patent application is configured to adjust the output current to a predetermined constant current magnitude in a continuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 38 of the patent application is configured to adjust the output current to a predetermined constant current magnitude in a critical conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing information associated with the current signal; based at least on the current Signal-associated information, at least by a capacitor to generate a voltage signal; processing information associated with the voltage signal and the sensed signal; generating a comparison signal based at least on information associated with the voltage signal and the sensed signal; receiving at least The comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting a drive signal based on at least information associated with the modulation signal; wherein: the drive signal is at least one or Associated with a plurality of switching cycles, each of the one or more switching cycles including at least an on time Processing for receiving at least the sensed signal includes: receiving at least the predetermined voltage signal during the on-time period for each of the one or more switching cycles; wherein the processing is associated with the current signal The processing of the associated information includes charging or discharging the capacitor by the current signal. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a first sample and hold and voltage to current conversion component configured to receive at least a sensed signal and generate a first current signal The sense signal is associated with an inductor current flowing through an inductor coupled to the first switch; a second sample and hold and voltage to current conversion component configured to receive at least the sense signal and generate a second current signal a signal amplification and voltage to current conversion component configured to receive at least the sensing signal and generate a third current signal; a current signal generator configured to generate a fourth current signal; a capacitor coupled to the current signal generator Connected to the first sample and hold and voltage to current conversion components and the second sample and hold and voltage to current conversion components by a second switch, and coupled to the signal amplification and voltage to current conversion by a third switch a component configured to generate a first voltage signal; a multiplier component configured to Generating information associated with the first voltage signal and the second voltage signal, and generating a multiplication signal based on at least information associated with the first voltage signal and the second voltage signal; a comparator configured to receive the multiplication signal and Sensing the signal and generating a comparison signal based at least on information associated with the multiplication signal and the sense signal; a modulation signal generator configured to receive at least the comparison signal and generate a modulation signal; and a gate driver, Configuring to receive the modulation signal and output a drive signal to the first switch; wherein: the drive signal is associated with at least a plurality of switching cycles, each cycle of the plurality of switching cycles including at least the first switch a time period and a demagnetization period for demagnetization processing; the first current signal representing an inductor current at the beginning of the on-time period; the second current signal representing an inductor current at the end of the on-time period; The third current signal represents the inductor current; wherein, for the plurality of switching cycles, the first current signal and the second current signal are Arranging to discharge or charge the capacitor only during the demagnetization period; the third current signal is configured to discharge or charge the capacitor only during the on-time period; and the fourth current signal is configured to be at the switch The capacitor is charged or discharged during the cycle. A system for providing at least an output current to one or more light emitting diodes according to claim 44, wherein, in the plurality of switching cycles, one switching cycle is multiplied by the fourth The current signal is equal to the first quantity and the second quantity of the first sum value, the first quantity being equal to the third current signal at the end of the corresponding on-time period multiplied by one-half of the corresponding on-time period, the second quantity being equal to The second sum value of the magnitude of the first current signal and the second current signal is multiplied by a corresponding demagnetization period. A system for providing at least an output current to one or more light emitting diodes as described in claim 44, wherein the signal amplification and voltage to current conversion component comprises a signal amplifying component and a voltage to current converting component . A system for providing at least an output current to one or more light emitting diodes as described in claim 44, wherein: the first sample and hold and voltage to current conversion component, the second sample and hold And a voltage to current conversion component, the signal amplification and voltage to current conversion component, the current signal generator, the multiplier component, the comparator, the modulation signal generator, and the gate driver are located on a wafer; and the The capacitor is located outside of the wafer. A system for providing at least an output current to one or more light emitting diodes as described in claim 44, configured to output the output current in a discontinuous conduction mode, a continuous conduction mode, and a critical conduction mode Adjust to a predetermined constant current size. A system for providing at least an output current to one or more light emitting diodes as described in claim 48, further configured to obtain equal to or greater than a discontinuous conduction mode, a continuous conduction mode, and a critical conduction mode. Power factor of 0.9. A system for providing at least an output current to one or more light emitting diodes as described in claim 44 of the patent application is configured to adjust the output current to a predetermined constant current magnitude in a discontinuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 50 of the patent application is further configured to obtain a power factor equal to or greater than 0.9 in the discontinuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 44, configured to adjust the output current to a predetermined constant current magnitude in a continuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 52 of the patent application is further configured to obtain a power factor equal to or greater than 0.9 in the continuous conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 44, configured to adjust the output current to a predetermined constant current magnitude in a critical conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 54 is configured to obtain a power factor equal to or greater than 0.9 in the critical conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal; generating a first current signal, a second current signal, and a third current signal based on at least information associated with the sensed signal; generating a fourth current signal; processing and the first current Information associated with the signal, the second current signal, the third current signal, and the fourth current signal; based at least on the first current signal, the second current signal, the third current signal, and the fourth current signal Associated information, generating at least a first voltage signal by a capacitor; processing information associated with the first voltage signal and the second voltage signal; based at least on information associated with the first voltage signal and the second voltage signal Generating a multiplication signal; receiving the multiplication signal and the sensing signal; generating a comparison signal based on at least information associated with the multiplication signal and the sensing signal Receiving at least the comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting a drive signal based on at least information associated with the modulation signal; wherein: the drive signal is at least Associated with a plurality of switching cycles, each of the plurality of switching cycles including at least an on-period and a demagnetization period; the first current signal representing an inductor current at a beginning of the on-time period; the second current signal Representing an inductor current at the end of the on-time period; the third current signal representing the inductor current; wherein, for each of the plurality of switching cycles, for processing the first current signal, the The processing of the information associated with the second current signal, the third current signal, and the fourth current signal includes: discharging or charging the capacitor by the first current signal and the second current signal only during the demagnetization period; Discharging or charging the capacitor by the third current signal during the on-time period; and passing the fourth current during the switching period No charging or discharging the capacitor. A method for providing at least an output current to one or more light emitting diodes as described in claim 56, wherein, in the plurality of switching cycles, one switching cycle is multiplied by the fourth The current signal is equal to the first quantity and the second quantity of the first sum value, the first quantity being equal to the third current signal at the end of the corresponding on-time period multiplied by one-half of the corresponding on-time period, the second quantity being equal to The second sum value of the magnitude of the first current signal and the second current signal is multiplied by a corresponding demagnetization period. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a transconductance amplifier configured to receive a sensing signal and also receive a predetermined voltage signal through a first switch, the sensing signal Associated with an inductor current flowing through an inductor coupled to a second switch, the transconductance amplifier is further configured to generate a current signal; a capacitor coupled to the transconductance amplifier and configured to generate a voltage signal; a comparator, Configuring to process information associated with the voltage signal and the ramp signal and generating a comparison signal based at least on information associated with the voltage signal and the ramp signal; a modulation signal generator configured to receive at least the comparison signal and generate a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the second switch; wherein: the drive signal is associated with at least one or more switching cycles, the one or more switching cycles Each cycle includes at least an on-time period of the second switch; the transconductance amplifier is further configured to One or more switching periods of each cycle, receiving at least a predetermined voltage signal only during the on period; current signal and configured to discharge or charge the capacitor. A system for providing at least an output current to one or more light emitting diodes as described in claim 58 wherein: the transconductance amplifier, the comparator, the modulation signal generator, and the gate The driver is on the wafer; and the capacitor is located outside the wafer. A system for providing at least an output current to one or more light emitting diodes as described in claim 58 of the patent application is configured to adjust the output current to a predetermined constant current magnitude in a critical conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 60, is further configured to obtain a power factor equal to or greater than 0.9 in the critical conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing information associated with the current signal; based at least on the current Signal-associated information, generating a voltage signal from at least a capacitor; processing information associated with the voltage signal and the ramp signal; generating a comparison signal based on at least information associated with the voltage signal and the ramp signal; receiving at least the comparison signal Generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and outputting a drive signal based at least on information associated with the modulation signal; wherein: the drive signal is coupled to at least one or more switches Associated with a period, each period of the one or more switching cycles includes at least an on period The processing for receiving at least the sensing signal includes receiving, at least during the period of the one or more switching cycles, the predetermined voltage signal during the on-time period; wherein the processing is associated with the current signal Processing of the information includes charging or discharging the capacitor by the current signal. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a transconductance amplifier configured to receive a sensing signal and also receive a predetermined voltage signal through a first switch, the sensing signal Associated with an inductor current flowing through an inductor coupled to a second switch, the transconductance amplifier is further configured to generate a current signal; a capacitor coupled to the transconductance amplifier and configured to generate a first voltage signal; multiplication And a device configured to process information associated with the first voltage signal and the sensed signal and to generate a multiplicate signal based on at least information associated with the first voltage signal and the sensed signal; a comparator configured Receiving the multiplication signal and the sensing signal, and generating a comparison signal based on at least information associated with the multiplication signal and the sensing signal; a modulation signal generator configured to receive at least the comparison signal and generate a modulated signal And a gate driver configured to receive the modulation signal and output a drive signal to the second switch; wherein: the driver The number is associated with at least one or more switching cycles, each of the one or more switching cycles including at least an on-time period of the second switch; the transconductance amplifier is further configured for the one or more switches Each cycle of the cycle receives at least a predetermined voltage signal during the on-time period; and the current signal is configured to charge or discharge the capacitor. A system for providing at least an output current to one or more light emitting diodes as described in claim 63, wherein: the transconductance amplifier, the multiplier component, the comparator, the modulated signal generation The gate and the gate driver are located on the wafer; and the capacitor is located outside the wafer. A system for providing at least an output current to one or more light emitting diodes as described in claim 63 of the patent application is configured to adjust the output current to a predetermined constant current magnitude in a critical conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 65 of the patent application is further configured to obtain a power factor equal to or greater than 0.9 in the critical conduction mode. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal and the predetermined voltage signal; generating a current signal based on at least information associated with the sensed signal and the predetermined voltage signal; processing information associated with the current signal; based at least on the current Signal-associated information, at least by a capacitor to generate a first voltage signal; processing information associated with the first voltage signal and the second voltage signal; based at least on a relationship associated with the first voltage signal and the second voltage signal Generating a multiplication signal; receiving the multiplication signal and the sensing signal; generating a comparison signal based on at least information associated with the multiplication signal and the sensing signal; receiving at least the comparison signal; based at least on information associated with the comparison signal Generating a modulated signal; receiving the modulated signal; and outputting based at least on information associated with the modulated signal a driving signal; wherein: the driving signal is associated with at least one or more switching cycles, each of the one or more switching cycles including at least an on-period; processing for receiving at least the sensing signal includes: Each of the one or more switching cycles receives at least the predetermined voltage signal during the on-time period; wherein processing for processing information associated with the current signal includes charging the capacitor by the current signal Or discharge. A system for providing at least an output current to one or more light emitting diodes, the system comprising: a first signal processing component configured to receive at least a sensing signal and generate a first signal, the sensing signal and the stream An inductor current coupled to an inductor coupled to the switch; a second signal processing component configured to generate a second signal; an integrator component configured to receive the first signal and the second signal and generate a third signal a comparator configured to process information associated with the third signal and the sensed signal and to generate a comparison signal based on at least information associated with the third signal and the sensed signal; a signal generator configured to Receiving at least the comparison signal and generating a modulation signal; and a gate driver configured to receive the modulation signal and output a drive signal to the switch; wherein the drive signal is associated with at least one or more switching cycles, the one Or each period of the plurality of switching cycles includes at least an on-period of the switch and a demagnetization period for demagnetization processing; wherein the first The number processing component is further configured to: sample each of the one or more switching cycles, sample the sensing signal in the middle of the one of the switching periods; and maintain the sampled to indicate that the inception period is in the middle a sensed signal of the inductor current; and generating the first signal indicative of a sum of the first multiplication result and the second multiplication result based on at least information associated with the sampled and held sensed signal; wherein Each of the one or more switching cycles, the second signal representing the switching period multiplied by a predetermined current magnitude; wherein: the integrator component is further configured to target the first signal and the second for a plurality of switching cycles The cycle-by-cycle difference between the signals is integrated; and the third signal represents the integrated cycle-by-cycle accumulated difference, the integrated cycle-by-cycle accumulated difference being less than a predetermined threshold in magnitude. A system for providing at least an output current to one or more light emitting diodes as described in claim 68, wherein the first multiplication result is equal to each cycle of the one or more switching cycles The sum of the first current magnitude and the second current magnitude is multiplied by an on-time period, the first current magnitude representing the inductor current at the beginning of the on-time period, the second current magnitude being indicated at the turn-on The inductor current at the end of the time period. A system for providing at least an output current to one or more light emitting diodes as described in claim 68, wherein the second multiplication result is equal to each cycle of the one or more switching cycles The sensed signal sampled and held is multiplied by the demagnetization period, and the sensed signal sampled and held represents the inductor current at the middle of the on-time period. A system for providing at least an output current to one or more light emitting diodes as described in claim 70, wherein the demagnetization period represents discontinuity for each of the one or more switching cycles The duration of the demagnetization process in the conduction mode and the critical conduction mode. A system for providing at least an output current to one or more light emitting diodes as described in claim 70, wherein for each cycle of the one or more switching cycles, the demagnetization is for a continuous conduction mode The time period is equal to the off time period of the switch. A method for providing at least an output current to one or more light emitting diodes, the method comprising: receiving at least a sense signal associated with an inductor current flowing through an inductor coupled to the switch; Processing information associated with the sensed signal; generating a first signal based on at least information associated with the sensed signal; generating a second signal; receiving the first signal and the second signal; processing and the first signal and Information associated with the second signal; generating a third signal based on at least information associated with the first signal and the second signal; processing information associated with the third signal and the sensed signal; based at least on The third signal and the information associated with the sensing signal generate a comparison signal; receiving at least the comparison signal; generating a modulation signal based on at least information associated with the comparison signal; receiving the modulation signal; and based at least on the modulation The signal associated information outputs a drive signal; wherein the drive signal is associated with at least one or more switching cycles, each week of the one or more switching cycles Included at least an on-period of the switch and a demagnetization period for demagnetization processing; wherein processing for processing information associated with the sensed signal comprises, for each period of the one or more switching cycles, Sampling the sense signal in the middle of the turn-on period; maintaining a sensed signal representative of the inductor current at the middle of the turn-on period; wherein, for each of the one or more switch cycles The first signal, based on at least information associated with the sensed signal that is sampled and held, represents a sum of a first multiplication result and a second multiplication result; the second signal represents the switching period multiplied by a predetermined current a size; wherein: processing for processing information associated with the first signal and the second signal comprises integrating a cycle-by-cycle difference between the first signal and the second signal for a plurality of switching cycles And the third signal represents the integrated cycle-by-cycle accumulated difference, the integrated cycle-by-cycle accumulated difference being smaller than a predetermined threshold in magnitude.